One might have thought that any mitzvah that Hashem commanded us to do is incumbent upon each and every person to fulfill themselves, with no possibility to “outsource” the fulfillment of the mitzva. Although this is true about many mitzvot, such as wearing tefillin or eating matza, there are certain cases when “outsourcing” is permitted by the Torah, and it is viewed as if the person himself fulfilled the mitzva. This essay will clarify the different methods given and when and how they apply.
Shelucho Shel Adam K’moto – A Person’s Agent is Considered Like the Person Himself
The Gemara in Kiddushin derives the principle that a person can appoint a shaliach on his behalf from the laws of korban pesach.
אמר רבי יהושע בן קרחה, מנין ששלוחו של אדם כמותו? שנאמר ושחטו אותו כל קהל עדת ישראל בין הערבים, וכי כל הקהל כולם שוחטין? והלא אינו שוחט אלא אחד! אלא מכאן ששלוחו של אדם כמותו.
Rabbi Yehoshua ben Korcha says: From where is it derived that the legal status of a person’s agent is like that of himself? As it is stated with regard to the Paschal offering: “And the whole assembly of the congregation of Israel shall slaughter it in the afternoon” (Shemot 12:6). Is it so that the whole assembly slaughters the offering? But only one person from each group slaughters it. Rather, it can be derived from here that the legal status of a person’s agent is like that of himself.
The Gemara explains here that since the verse states that the entire community needs to slaughter the animal despite the fact that only one person per group actually performs the slaughter, we derive that one person slaughtering it on behalf of others is considered as if each person slaughtered the korban, and thereby fulfills the mitzva. The Gemara in this sugya also quotes two other sources in the Torah that prove that agency is a possible method of fulfilling a mitzva. One of these is the institution of teruma and ma’aser, while the other is divorce. Concerning teruma, the verse states:
כֵּ֣ן תָּרִ֤ימוּ גַם־אַתֶּם֙ תְּרוּמַ֣ת יְקֹוָ֔ק מִכֹּל֙ מַעְשְׂרֹ֣תֵיכֶ֔ם אֲשֶׁ֣ר תִּקְח֔וּ מֵאֵ֖ת בְּנֵ֣י יִשְׂרָאֵ֑ל וּנְתַתֶּ֤ם מִמֶּ֙נּוּ֙ אֶת־תְּרוּמַ֣ת יְקֹוָ֔ק לְאַהֲרֹ֖ן הַכֹּהֵֽן:
“So you also should set aside a gift for the Lord from all the tithes you take from the children of Israel, and you shall give the Lord’s gift from it to Aharon the priest.”
The Gemara expounds that the redundant word “also” indicates that an agent is also permitted to tithe on behalf of the owner. With regard to divorce, the Gemara derives from the use of the word “v’shilcha,” “and he sends her” (as opposed to stating that he will divorce her using the word v’girsha), that he may “send” a shaliach to bring her the get (divorce document).
The Gemara asks why the Torah needed to demonstrate this principle of agency regarding tithes, the korban pesach, as well as divorce, and concludes that each case is unique and could not have served as the binyan av (model case) for all cases in the Torah.
Zachin L’adam Shelo Befanav – Acting in a Person’s Interest in his Absence
Until this point, we have seen that a person can knowingly appoint another person to fulfill certain types of mitzvot on his behalf. In these cases, the agent acts on behalf of the owner/sender and with the knowledge and consent of the owner/sender. The Gemara in the continuation of the sugya then introduces another type of case – where the owner is not aware of and has not consented to the agent acting on his or her behalf. This is called zachin l’adam shelo befanav in a case where it is assumed that the action is to the benefit of the recipient, and is legally valid.
Before introducing this case, the Gemara suggests that the general principle of shelichut can also be derived (in addition to from the three verses mentioned above) from a verse demonstrating that each nasi (prince) of the tribes of Israel was appointed as the agent for his tribe when dividing the land of Israel following its conquest by Yehoshua. However, the Gemara refutes this, since shelichut cannot be done on behalf of a minor. Since the nesi’im also received land on behalf of minors, the Gemara concludes that it must be effective based on this mechanism of zachin l’adam shelo befanav.
Does Zechiya Stem from Shelichut?
The Opinion of Rashi
From the simple reading of the text, it appears that the principles of shelichut and zechiya are not assumed by the Gemara to be identical, as the Gemara retracts using the verse concerning the nesi’im as a source for shelichut and suggests instead that it serve as the source for zachin. This is indeed how Rashi seems to understand the sugya. In another sugya, Rashi again highlights the difference between zachin and shlichut. The Gemara discusses a case of “tofes l’baal chov bimkom shechav l’acherim,” one who reclaims a loan for a creditor where the debtor owed many other creditors as well. In such a case, if there would not be any money left for the other creditors, the Gemara states that a person cannot act in the interest of one creditor. Rashi explains that the reason such an action is not valid is that the creditor did not appoint this individual to serve as his agent. Hence, the mechanism of shelichut cannot been used (though had he in fact appointed him, the shelichut would have been valid despite being to the detriment of others). Rather, it seems from Rashi that the operative principle can only be that of zachin, which has different rules than that of shelichut, and can only take effect when it is not to the detriment of others. Therefore, in this case, where it invariably causes a loss to others, the creditor in question does not acquire the money.
The Opinion of the Rashba
The Rashba similarly holds that the mechanism of zechiya is independent of the principle of shelichut. The Rashba states that an integral part of shelichut is that the sender knows and appoints the agent. The Rashba highlights this regarding the Gemara in Nedarim that asks whether one can tithe one’s own produce in order to exempt the produce of someone else. The Gemara posits the question as follows: “Do we say that since it is a benefit for him [to have his produce tithed] it does not require his knowledge, or perhaps it is his mitzva, and he prefers to perform the mitzvah himself?” The Rashba points out that if the ability to separate teruma for another is based on shelichut, then why does the Gemara invoke the consideration that the tithing is to the person’s benefit? After all, shelichut is unconnected to whether the action benefits the person or not – if the person authorizes another to be his agent, the act is valid regardless of whether it benefits him or it is to his detriment. The Rashba explains that where a person is separating teruma from his own produce for someone else rather than the other person’s produce on their behalf, the mechanism of shelichut is not required, but only the knowledge that it is a zechut for him and in his best interests. Therefore, the Gemara in Nedarim is only concerned with whether the principle of zachin applies or not. It is evident from the Rashba’s discussion that he understood zechiya to be a completely different mechanism than shelichut, with its own rules and definitions.
The Opinion of Tosafot
In contrast to Rashi and the Rashba, Tosafot and Tosafot Rosh hold that the principle of zachin is part of the greater principle of shelichut. In contrast to Rashi, Tosafot explain that in the case of tofes l’ba’al chov, where the Gemara stated that a person may not claim a debt on behalf of one creditor where it is to the detriment of others, there is no difference whether the first creditor appointed this person as his agent or not. Rather, Tosafot hold that the principle of zachin works as part of the principle of shelichut, yet the Sages instituted a rule that one cannot activate shelichut where it will be to the detriment of another.
Tosafot marshal support for their opinion from the Gemara in Nedarim discussed above, presumably based on the fact that the Gemara employs principles of zachin within the context of one individual separating teruma on behalf of another, which is a classic case of shelichut based on the Gemara in Kiddushin.
The Basis for the Machloket
Let us summarize what we have learned so far. We have seen that Rashi and Rashba hold that the principle of zechiya is independent of the principle of shelichut and possesses its own halachic parameters. Rashi’s opinion is evident from his following the simple interpretation of the Gemara in Kiddushin, which originally attempts to derive the principle of shelichut from the verse regarding the division of the land, but then appears to retract and instead employs the verse as a source for the principle of zachin. The Rashba’s opinion is apparent from his question and explanation of the Gemara in Nedarim that invokes zachin with regard to tithing one’s own produce on behalf of another even without their knowledge. According to this approach, the notion that one may act on behalf of another only when it is to their benefit is a rule limited to zechiya only, but not to shelichut.
On the other hand, Tosafot and the Rosh understand that the principle of zachin is included in the principle of shelichut and therefore the same parameters would apply. One of their proofs for this is from the very same Gemara in Nedarim that the Rashba felt must be understood in line with his approach. Accordingly, they must hold that when it is considered a benefit to the recipient, it is as if there is da’at (intent), just as is necessary for standard cases of shelichut. However, even shelichut does not take effect when the act is to the detriment of others, such as in the case in the Gemara in Gittin of hatofes l’ba’al chov b’makom shechav l’acharinei.
Perhaps the point of argument between the Rishonim is what the function of benefit to the person creates. Is the benefit received considered equivalent to some type of virtual knowledge and appointment by the recipient (just like shelichut — Tosafot), or is the function of benefit in that it allows for the independent mechanism of acquisition to take place (independent of shelichut — Rashi)? Just as there are other mechanisms through which an object can be acquired for a person without his knowledge, such as yerusha (inheritance), so too here perhaps zachin acquires on a person’s behalf without his knowledge or appointment. However as opposed to yerusha, where there is no limitation to this method of acquisition, here this mechanism only works if it is to one’s benefit (and perhaps not to the detriment of others).
Zachin L’adam in a Case of Loss
With the above background, we can now better appreciate the machloket discussed in the shiur between the Terumat HaDeshen and the Ketzot HaChoshen regarding zechiya in the context of hafrashat challa. The Terumat HaDeshen was asked about a case where a Jewish maidservant was alone without the ba’alat habayit (homeowner). The servant realized that the woman had forgotten to separate challa from dough that was to be baked into bread, and if she did not separate it in her stead and begin baking the bread, the dough would go sour. The question posed to the Terumat HaDeshen was whether the servant was permitted to separate the challa even though she was not appointed by the owner. The Terumat HaDeshen answered that due to the principle of zachin le’adam shelo b’fanav, which he holds is based on shelichut, in accordance with the opinion of Tosafot and the Rosh, it would be permitted for her to do so, since the mitzva of hafrashat challa may be performed by another using the principle of shelichut (since it is equivalent to teruma).
In contrast, the Ketzot HaChoshen argues that the practical halacha is that the principle of zachin is not derived from the principle of shelichut, but they are two independent mechanisms, in accordance with Rashi and the Rashba. If so, the maidservant may not separate challa for the ba’alat habayit, since the ba’alat habayit did not authorize her to do so (using shelichut), and there is no explicit source that zachin applies to the mitzvah of challa. The Ketzot explains that zachin only applies where there is an absolute benefit to the recipient of the act, such as in the Gemara Nedarim where the one separating teruma did so from his own produce. However, in the case of the maidservant, the Rashba would agree that we cannot apply the principle of zachin since it is essentially “zachin me’adam,” benefitting a person by taking something from him, as he is subjected to the financial loss of the challa separated. In such a case, it is not considered a complete benefit, and only shelichut can be employed when the owner authorizes the separation, but not zachin without their knowledge.
 Kiddushin 41a- 41b
 Bamidbar 18:28
 Devarim 25:1
 Kiddushin 42a
 Bamidbar 34:18
 The halacha that shelichut does not apply to a minor is derived by the Gemara in Bava Metzia (71b) from the verse “vshalach vshalacha, which includes a shaliach.
 When the Gemara retracts the suggestion of deriving shelichut from the verse of the nesi’im, Rashi (s.v. ela) states that this verse “does not come to include the institution of agency [as being valid], but rather serves to include the principle of zachin l’adam shelo b’fanav.” This formulation would seem to indicate that the two principles are not identical. This is supported by Rashi’s next comment (s.v. ela k’derava) on the continuation of the Gemara, where the Gemara questions deriving zachin from here and concludes that in fact the verse teaches that orphans are provided with an apotrepos. Here, Rashi attempts to explain how the Gemara derives both the principle of zachin and the rule about the apotrepos from this same pasuk. The contrast between Rashi’s understanding of the two stages of the Gemara further highlights the fact that Rashi seems to have interpreted zachin as distinct from shelichut. This is the explanation of Rav Zalman Nechemia Goldberg to Rashi’s approach, as recorded in his shiut on the “Yeshiva” website (https://www.yeshiva.org.il/midrash/39620).
 Bava Metzia 10a
 Rashi, ibid., s.v. lo kana
 Rashba, Nedarim 36b; cf. Rashba, Kiddushin 42a, where he discusses the opinion that zechiya is included in the mechanism of shelichut and cites the Gemara in Nedarim as proof of that position.
 Nedarim 36b
 Tosafot, Gittin 11b, s.v. hatofes l’ba’al chov
 Tosafot Rosh, Kiddushin 42a, s.v. ela
 Responsa Terumat HaDeshen 180
 Ketzot HaChoshen, C.M. 243:8