Source of Ta’aseh V’lo Min Ha’asuy
Several mitzvot in the Torah require one to fashion an object either in preparation for, or performance of, that mitzvah. For example, in order to perform the mitzvah of wearing a garment with tzitzit, one must tie strings to a four-cornered garment. In some of these mitzvot, Chazal understood that the formulation of the Torah obligates a person to ensure that the object is made actively by him and does not simply get completed automatically, a rule known as ta’aseh v’lo min ha’asuy. For example, concerning tzitzit, the Torah commands: “Gedilim ta’aseh lach,” “you shall make for yourself strings [i.e., tzitzit],” and the Talmud extrapolates “ta’aseh — v’lo min ha’asuy,” “you shall make [the tzitzit] – and not from that which is already made.” In other words, the Torah requires that tzitzit be actively fashioned as opposed to passively made of their own accord.
Practically, this means that one should only affix the tzitzit strings to a garment after all the conditions that obligate the garment in tzitzit have been met. If one ties strings to the garment before it is fully obligated in tzitzit, then at the point at which the obligation to add tzitzit takes effect, the tzitzit are considered “asuy,” already made (as if of their own accord), and are therefore invalid. The Torah also uses the language “ta’aseh” with regard to the mitzvah of sukka. Accordingly, the Talmud understands that the rule of “ta’aseh v’lo min ha’asuy” applies to the mitzvah of sukka as well.
Surprisingly, the Talmud rules that the requirement of ta’aseh v’lo min ha’asuy also applies to the mitzvah of mezuza:
תנא: העמיד לה מלבן של קנים, חותך שפופרת ומניחה. אמר רב אחא בריה דרבא: לא שנו אלא שהעמיד ולבסוף חתך והניחה, אבל חתך והניח ולבסוף העמיד – פסולה, תעשה – ולא מן העשוי.
It was taught [in a baraita]: If one attached [to his house] a doorframe of reed, he should cut [a hole] in the tubing [of the reed] and place the mezuza inside it. Rav Acha son of Rava said: It was only taught [that the mezuza is valid in such a case] if he attached [the doorframe] and then hollowed it and placed the mezuza inside, but if he [first] hollowed the reed and placed the mezuza inside and then attached it [to the house], it is invalid [because of] “you shall make” – and not from that which is already made.
The Talmud makes it clear that the doorframe must first be attached to the house so that it is fully obligated in mezuza, and only then may the mezuza be affixed to the frame. If the order is reversed, by the time the doorframe becomes obligated in mezuza (i.e. when it is attached to the house), the mezuza has already been passively placed, resulting in a violation of ta’aseh v’lo min ha’asuy. The application of this pesul (disqualification) to the mitzvah of mezuza is puzzling because the word ta’aseh does not appear in either of the two instances in which the mitzvah of mezuza is commanded. If the word ta’aseh does not appear in the context of mezuza, how can the Talmud extrapolate the halacha of v’lo min ha’asuy?
Rashi explains that the requirement of ta’aseh v’lo min ha’asuy concerning mezuza is derived from the mitzvah of tzitzit: Just as the Torah requires that tzitzit be actively made, so, too, other mitzvot that have a component of asiya, fashioning, must be made in an active manner. The Levush offers a different explanation based on the wording of the commandment of mezuza. Since the Torah’s formulation is, “uchetavtam al mezuzot beitecha,” “You shall write them [i.e. these words] on the doorposts of your houses,” the implication is that the doorpost must already be attached to the house before the mezuza is affixed. The Talmud uses the phrase ta’aseh v’lo min ha’asuy for the sake of convenience, but in actuality the law as it applies to mezuza is derived from the wording used for the mitzvah of mezuza itself.
Regardless of the source, this halacha is codified in the Shulchan Aruch:
קבעה במזוזת הפתח, בעודה תלושה, ואחר כך חברה לפתח פסולה.
If he attached it to the doorframe while it [i.e. the doorframe] was still detached [from the house] and then attached the doorframe [to the house], it is invalid.”
Parameters of Ta’aseh V’lo min Ha’asuy
It is conceivable that a mezuza may be initially affixed in a kosher, active manner but have its validity later called into question because of ta’aseh v’lo min ha’asuy. Specifically, the mezuza may be affixed at a time when the house was obligated in the mitzvah of mezuza, but later the house may become exempt and then subsequently re-obligated, with the mezuza all the while remaining attached. On the one hand, since the mezuza was originally affixed in a valid fashion, perhaps it remains valid despite the intervening time when the house was not obligated. On the other hand, perhaps because at the point at which the house became re-obligated in mezuza, the mezuza was already affixed, the mezuza is invalid due to ta’aseh v’lo min ha’asuy, regardless of the fact that it was originally kosher.
For example, a mezuza is properly affixed to the doorway of a house, but then the roof blows off the house, which exempts if from the obligation of mezuza. When the roof is repaired, is the mezuza now invalid and in requirement of reattachment due to ta’aseh v’lo min ha’asuy, or does it remain valid? It would seem that the critical question in this case is whether the disqualification of ta’aseh v’lo min ha’asuy applies only during the initial fashioning or throughout the existence of the mezuza.
While there are no passages in the Talmud that address this question with regard to the mitzvah of mezuza, there is a relevant passage with regard to tzitzit. Based on the precedent set forth by the Talmud and Rishonim with regard to Hilchot Tzitzit, the Acharonim attempt to apply the law with regard to Hilchot Mezuza as well.
The Talmud records the following discussion:
אמר רחבה אמר ר’ יהודה: טלית שנקרעה, חוץ לשלש – יתפור, תוך שלש – לא יתפור. תניא נמי הכי: טלית שנקרעה, חוץ לשלש – יתפור, תוך שלש – רבי מאיר אומר: לא יתפור, וחכ”א: יתפור; ושוין, שלא יביא אפילו אמה על אמה ממקום אחר ובה תכלת ותולה בה; ושוין, שמביא תכלת ממקום אחר ותולה בה, ובלבד שלא תהא מופסקת.
Rechava said in the name of Rav Yehuda: A garment that ripped, [if the rip is] outside of three [fingerbreadths from the edge of the garment] he may sew it; [if the rip is] within three [fingerbreadths of the edge of the garment] he may not sew it. It was likewise taught in a baraita: A garment which ripped, [if the rip is] outside of three [fingerbreadths from the edge of the garment] he may sew it; [if the rip is] within three [fingerbreadths of the edge of the garment], Rabbi Meir says he may not sew it and the Chachamim say he may sew it. [Rabbi Meir and the Chachamim] are in agreement that he may not bring from elsewhere [fabric] even measuring a square amah [cubit] with techeilet [i.e. with tzitzit strings] attached and connect it [to the ripped garment]. [Rabbi Meir and the Chachamim are also] in agreement that he may bring techeilet [i.e., tzitzit strings] from elsewhere and attach it to [the ripped garment] as long as the strings are not broken [i.e. they meet the minimum required length].”
The cryptic baraita quoted in the passage above describes three cases. The Rishonim agree as to the correct explanation and interpretation of the last case: All (Rabbi Meir and Chachamim) agree that it is permitted to remove tzitzit strings from one garment and tie them to a new garment. There is no potential problem of ta’aseh v’lo min ha’asuy in this case because it is necessary to actively tie the strings to the new garment. However, the explanation and reasoning behind the first two cases in the baraita are subject to dispute among the Rishonim.
Rashi and Rosh
According to Rashi, the baraita initially discusses a tallit she’eina metzuyetzet, a garment without tzitzit, which rips. According to Rav Yehuda and Rabbi Meir, if the garment rips within three fingerbreadths of the edge, it may not be repaired out of concern that after sewing the two pieces together, one may leave the dangling thread used to sew the garment as one of the tzitzit strings and simply add more strings to the already present thread to complete the requisite amount of tzitzit strings. This would be invalid because of ta’aseh v’lo min ha’asuy, as the sewing thread was attached initially not as a tzitzit string, but rather to repair the garment and only later designated as a tzitzit string. The Chachamim permit the garment to be repaired because they are not concerned that the sewing thread will be used as a tzitzit string. All agree that if the garment rips outside of three fingerbreadths from the edge, it may be repaired, and there is no concern that the sewing thread will be used as a tzitzit string, because tzitzit strings must be located at the very edge of the garment, within three fingerbreadths from the end. Although this case has little bearing on Hilchot Mezuza, an important qualification of the rule of ta’aseh v’lo min ha’asuy with ramifications to Hilchot Mezuza emerges by contrasting Rashi’s explanation of the second case in the baraita with his explanation of the first case.
The next case in the baraita discusses sewing a large piece of fabric with preexisting tzitzit to a ripped garment, according to Rashi. Here, all agree that one may not fashion a garment in such a way, but the reason Rashi provides is intriguing. Rashi does not, as may have been expected, write that the problem here is one of ta’aseh v’lo min ha’asuy. Rather, he explains:
משום דעל כנפי בגדיהם בעינן וכנף זה לא היה מבגד זה בשעת עשייה.
Because we require (based on Bamidbar 15:38) “al kanfei bigdeihem” (on the edges of their garments), and this edge did not belong to this garment at the time [the tzitzit] were made.”
Instead of explaining that the tzitzit are invalid because of ta’aseh v’lo min ha’asuy, Rashi provides a reason that is specific to Hilchot Tzitzit: The Torah requires that tzitzit be placed al kanfei bigdeihem,” and therefore the edge must be attached to the garment before the tzitzit are attached. Considering that in the previous case of the baraita, Rashi explained that Rabbi Meir and the Chachamim argued about ta’aseh v’lo min ha’asuy and Rashi now ignores this principle and resorts to a tzitzit-specific rule, we are forced to conclude that according to Rashi, the principle of ta’aseh v’lo min ha’asuy is not operational in this case. It seems that Rashi holds that as long as the original fashioning was performed in an active, kosher manner, even if a passive fashioning subsequently occurs, the disqualification of ta’aseh v’lo min ha’asuy does not apply. Since the tzitzit were originally tied to the fabric in a proper fashion, when the fabric is later attached to the ripped garment, it is not invalid due to ta’aseh v’lo min ha’asuy, but rather due to a local rule governing Hilchot Tzitzit (al kanfei bigdeihem). The important implication for Hilchot Mezuza is that once a mezuza is affixed to a doorpost that is obligated in mezuza, it avoids any future issues of ta’aseh v’lo min ha’asuy. Thus, if the house later becomes exempt from mezuza and then re-obligated in it, or even if the whole doorpost (with the mezuza) is removed from the wall and placed in a new wall, the mezuza will remain valid. The explanation of Rashi is echoed by the Rosh.
Rav Amram Gaon and Nimmukei Yosef
Rav Amram Gaon, cited by Nimmukei Yosef, offers a different interpretation of the baraita. According to Rav Amram Gaon, the first case of the baraita deals with a tallit hametzuyetzet, a garment with tzitzit, that rips. Rav Yehuda and the Chachamim hold that if the garment rips within three fingerbreadths of the edge, the ripped piece with the tzitzit may not be reattached to the garment because of ta’aseh v’lo min ha’asuy; the small size of the piece (measuring less than three by three fingerbreadths) renders it insignificant such that the tzitzit strings are no longer considered attached to a kanaf, a corner of a garment. Thus, if the small piece is sewn back onto the garment, the tzitzit are now once again attached to a valid kanaf, but not through an active tying process, and are therefore invalid because of ta’aseh v’lo min ha’asuy. If the garment rips outside of three fingerbreadths from the edge, the resulting piece is large enough that the tzitzit are still considered attached to a kanaf. Therefore, the piece may be reattached to the garment and there is no concern of ta’aseh v’lo min ha’asuy.
The next case in the baraita, explains Rav Amram, discusses fixing a garment with tzitzit that has a large hole in the middle of it by bringing a large piece of fabric without tzitzit from elsewhere and sewing it to the inside of the garment. In such a case, everyone agrees that the garment is not kosher because of ta’aseh v’lo min ha’asuy.
Analyzing the two cases of the baraita according to the explanation of Rav Amram Gaon reveals a significant rule about when the pesul of ta’aseh v’lo min ha’asuy applies. If one is restoring a previous status quo, such as reattaching the ripped kanaf to the garment from which it ripped, then as long as the item was originally fashioned in a kosher manner, there is no subsequent issue of ta’aseh v’lo min ha’asuy. If, however, one is creating a new status quo, such as attaching a garment with tzitzit to a new piece of fabric, then the item is disqualified based on ta’aseh v’lo min ha’asuy. Put differently, the disqualification of ta’aseh v’lo min ha’asuy only applies during the initial fashioning of the object and not if it is subsequently dismantled and reassembled, but only so long as that object remains as originally designed. If the object is dismantled and then reassembled from non-original components, it is considered a new fashioning and the pesul of ta’aseh v’lo min ha’asuy is applicable.
Translating this rule into Hilchot Mezuza, if a mezuza was put up properly and then the house became exempt and re-obligated, the mezuza remains kosher. Since the mezuza was kosher at the initial stage and the previous status quo is restored, there is no problem of ta’aseh v’lo min ha’asuy. In fact, even if the entire doorframe with the mezuza was removed from the wall and then replaced in the same place, the mezuza would remain kosher, as the situation was returned to the status quo. However, if the doorframe with the mezuza was removed from one wall and returned to another wall, the mezuza would be invalid due to ta’aseh v’lo min ha’asuy, as the structure was reassembled from non-original components.
An ambiguous statement of the Mordechai in explanation of this passage may indicate that he takes a third approach regarding the parameters of ta’aseh v’lo min ha’asuy. The Mordechai concurs with Rashi’s explanation of the first case in the baraita, but with regard to the second case the Mordechai posits as follows:
ושוין שלא יביא אפילו אמה על אמה ממקום אחר ובה תכלת ויתלה בה – ודוקא להביא ממקום אחר דודאי ה”ל תעשה ולא מן העשוי, אבל אם הוא נקרע למעלה משלשה ועדיין מחובר לבגד מותר לתפור.
“[The baraita states:] They agree that he should not bring even a square amah [of fabric] with techeilet from elsewhere and attach it [to the ripped garment] – It is specifically [problematic] to bring [the fabric] from elsewhere because that certainly is considered ta’aseh v’lo min ha’asuy, but if the garment ripped outside of three [fingerbreadths from the edge] and [the edge] is still connected to the garment, it is permissible to sew it.
Ostensibly, the words of the Mordechai are somewhat contradictory, as conflicting inferences can be drawn from the beginning and end of his statement. He first writes that ta’aseh v’lo min ha’asuy applies only when one attaches the garment to a fabric with tzitzit brought from elsewhere, clearly implying that there would be no issue of ta’aseh v’lo min ha’asuy to simply reattach a ripped corner to the garment from which it ripped. That conclusion would make the Mordechai’s position identical to that of Rav Amram Gaon and Nimmukei Yosef. However, he concludes that it is permissible to sew a ripped corner of a garment if it is still partially attached to the garment, implying that were the corner to be fully detached from the garment, one would not be allowed to repair it, despite the fact that the corner and the garment were previously attached to each other.
Two approaches are found in the commentaries to resolve this contradiction. The Maharam Mintz explains that according to the Mordechai, the law is dependent on the intention of the owner of the garment. If when the garment ripped he planned to repair it, then even if it ripped fully, he may sew it back together with no concern for ta’aseh v’lo min ha’asuy. If, however, when the garment ripped he did not plan to repair it and subsequently he changed his mind and decided to repair it, his “repair” of the garment is considered a new fashioning and is therefore subject to the pesul of ta’aseh v’lo min ha’asuy, unless there is another factor which proves that this is a restoration of the status quo and not a new fashioning, such as if the corner is still partially attached to the garment.
A second explanation is offered by the Torat Emet that the end of the Mordechai’s statement provides the real operating principle: The corner of the garment may only be sewn back on if it is still partially attached to the garment; otherwise, the tzitzit will be invalid due to ta’aseh v’lo min ha’asuy. When he writes that ta’aseh v’lo min ha’asuy applies only when the fabric is brought from elsewhere, he relies on the reader to finish the sentence and conclude that anything other than reattaching a partially ripped corner is akin to bringing a fabric from elsewhere. According to this understanding, the Mordechai is advancing a third position with regard to ta’aseh v’lo min ha’asuy after the initial fashioning. Even if one is restoring the previous status quo and not creating a new object, ta’aseh v’lo min ha’asuy nonetheless applies unless the object is still partially connected. Thus, if one were to remove the doorframe with the mezuza from the wall and then return it to the same place, the mezuza would be invalid since the doorframe was completely detached in the interim.
Applications To Hilchot Mezuza
Equipped with this understanding of the dispute between the Rishonim regarding the parameters of ta’aseh v’lo min ha’asuy, we can now explore applications to Hilchot Mezuza. One application, albeit an uncommon one, has already been demonstrated. If, after initially affixing a mezuza in a proper manner, the doorframe (and the mezuza) was removed from the house, Rashi and the Rosh would permit the doorframe to be moved even to a new house, Rav Amram Gaon and the Nimmukei Yosef would only permit the doorframe to be reattached to the wall from which it came, and the Mordechai (according to the Torat Emet) would not permit it to be reattached anywhere. Three applications which are more prevalent are now presented.
It was once common to build a sukka by simply replacing the year-round roof of one of the rooms of the house with kosher schach. Assuming that during Sukkot the room becomes exempt from the obligation of mezuza, what is the status of the mezuza after Sukkot, once the permanent roof is replaced and the room is returned to its regular condition? Now that the room is re-obligated in mezuza, must the mezuza be detached and reattached to avoid the problem of ta’aseh v’lo min ha’asuy? According to the above analysis, this is not necessary. Even according to the Torat Emet’s understanding of the Mordechai, because the doorframe remained attached to the house the entire time, there is no issue of ta’aseh v’lo min ha’asuy. This is indeed the ruling of Arba’a Turei Even.
A second, similar, scenario involves repairing the door of an entranceway that has a mezuzah on it. According to the Rambam, an entranceway is only obligated to have a mezuza if it has a door. According to this opinion, which receives mention in the Shulchan Aruch, if a mezuza is affixed to the doorframe before the door is attached, it is invalid due to ta’aseh v’lo min ha’asuy since the mezuza was put up before the obligation set in. Thus, a situation very similar to the previous case can arise when a mezuza is properly affixed (after the door is put up) and then the door is removed for repairs. When the door is reattached, is the mezuza now invalid according to the Rambam because of ta’aseh v’lo min ha’asuy? Here, too, all of the Rishonim, including the Mordechai (even according to the stringent interpretation), will agree that because the mezuza was initially fashioned correctly and the doorframe remained attached to the house the entire time, there is no issue of ta’aseh v’lo min ha’asuy when the door is reattached.
A third application found in the Hagahot Maimoniot relates to an entrance with a double door that is built with a post that separates between the two doors. The door on the right (when standing outside facing inside) usually remains closed, such that the mezuza is placed on the post which separates the two doors, which is to the right of the left-hand door. On rare occasions, the door on the right is opened and the dividing post is removed (with the mezuza) from the doorway to allow passage for large deliveries. Afterwards, the post is then put back in its place and the doorway resumes its normal function. The Hagahot Maimoniot rules that even after the middle beam is removed and then reattached, the mezuza remains valid because ta’aseh v’lo min ha’asuy does not apply when the doorframe is restored to its original state, provided that the mezuza was originally properly affixed. The Hagahot Maimoniot appears to agree with Rav Amram Gaon and Maharam Mintz’s interpretation of the Mordechai; as long as the original status quo is restored, the object remains kosher even if it was dismantled in the interim. According to the Torat Emet’s explanation of the Mordechai, however, the mezuza in this case would be invalid due to ta’aseh v’lo min ha’asuy and it would be necessary to remove and reattach the mezuza. Because the center beam was completely detached from the doorway, the subsequent reattachment is considered a new fashioning and is therefore subject to ta’aseh v’lo min ha’asuy.
 Devarim 22:12
 Menachot 40b
 Sukka 11b
 Menachot 33b
 See Maharshag, Y.D. 57.
 Menachot 33a, s.v. teli
 Although we find no explicit derasha connecting tzitzit to mezuza, the Be’er David (32) explains that Rashi means that mezuza is derived from tzitzit through a binyan av, a prototypical case where the law stated in the prototype can be assumed to apply to all similar cases. See Sukka 11b and Rashi there (s.v. v’yalfinan) for a parallel binyan av between sukka and lulav.
 Y.D. 289:5. The Sefer Yere’im (400) also suggests that there is a local derasha from the pesukim of mezuza, though his derasha is slightly different.
 Devarim 6:9, 11:20
 Y.D. 289:5
 Menachot 33b, Yoma 11b, Shulchan Aruch, Y.D. 286:14
 Menachot 41a-b
 It seems puzzling that the Talmud supports the opinion of Rav Yehuda by citing a baraita in which the majority view (Chachamim) actually opposes his view and only the minority view (Rabbi Meir) agrees with him. The Beit Yosef (O.C. 15) quotes Hagahot Maimoniot, who explains that the halacha follows Rabbi Meir in this instance based on the rule (Ketubot 57a) “halacha k’Rabbi Meir b’gezeirotav” (see Rashi’s explanation of this passage below that Rabbi Meir’s position is based on a gezeira). In the Rif and Nimmukei Yosef’s version of the text (12a in pagination of the Rif), the opinions of Rabbi Meir and Chachamim are reversed, thus resolving the difficulty.
 The Rif’s version of the baraita omits the words “תכלת ובה,” “with techeilet attached.” Accordingly, the baraita is referring to bringing a plain piece of fabric to attach to a garment with tzitzit as opposed to bringing a fabric with tzitzit to attach to the garment with tzitzit.
 Menachot 41a, s.v. “yitfor” and “lo yitfor”
 It appears from this comment of Rashi that barring the issue of ta’aseh v’lo min ha’asuy described here, it is permissible to attach a tzitzit string by sewing it into the garment and it is not necessary to put it through a hole in that garment and tie it, as is commonly done today. See, however, Taz, O.C. 12:3 and Chazon Ish, O.C. 3:11.
 Menachot 41b, Shulchan Aruch O.C. 11:9
 This piece of fabric was also presumably once part of a garment that was subject to the obligation of tzitzit.
 Menachot 41a, s.v. mimakom acheir
 This is indeed how Teshuvot Torat Emet 232 understands Rashi and the Rosh. See, however, Teshuvot Maharam Mintz 13 for a different understanding. See also Magen Avraham, O.C. 15:3.
 Hilchot Tzitzit 11
 12a in the pagination of the Rif
 See footnote 13.
 See footnote 14.
 Teshuvot Maharam Mintz 13
 Teshuvot Torat Emet 232
 It should be noted that the validity of this assumption is debated. On the one hand, the Talmud (Yoma 11a-b) states that a sukka on Sukkot is exempt from mezuza because it is only a temporary dwelling (dirat arai). On the other hand, perhaps a sukka is only exempt from the obligation of mezuza when it is built specifically for Sukkot, in which case it has the status of dirat arai, but when it is a permanent structure year-round, it is considered a permanent dwelling (dirat keva) and is obligated in mezuza. The Sha’arei Teshuva (O.C. 627:7), citing the Pri Chadash, the Ketav Sofer (Y.D. 139), and the Mishna Berura (O.C. 626:21) maintain that the sukka is exempt. By contrast, the Arba’a Turei Even (14) and the Mateh Efraim (625:27) maintain that the sukka is obligated.
 Siman 14. See, however, Ketav Sofer (Y.D. 139).
 Hilchot Mezuza 6:1
 Y.D. 286:15
 Shach 286:25
 Arba’a Turei Even and Pitchei Teshuva, Y.D. 286:14 quoting R. Yaakov of Lisa. See, however, Ketav Sofer, Y.D. 139.
 Hilchot Mezuza 6:6
 See Maharshag 57, who also rules stringently.