In this essay, we will trace some of the basic sources and halachot concerning the process of conversion as they appear in the Gemara, Rishonim, and Shulchan Aruch.
Basic Conditions for Conversion
A lengthy baraita describes the process that a gentile must undergo in order to convert to Judaism in detail. Here are some of the major points:
- First the dayanim (judges) ask him: “What did you see that made you come to convert?”, as during this period in history, it is difficult for Am Yisrael, being dispersed among the nations and experiencing great suffering. If he says that he knows the situation of Am Yisrael and still declares “איני כדאי – I am not worthy”, i.e., I am not deemed worthy of joining them, even though they are in such a humiliated condition – “מיד מקבלים אותו – we immediately accept him” – and move onto the next stage.
- The dayanim inform him of some of the easy mitzvot and some of the more difficult ones. They tell him about leket, shichecha and pe’ah and the punishment given for transgressing certain mitzvot. They also tell him that tzaddikim receive their rewards in the next world and not in this world. Despite this intense detail, the baraita emphasizes that “אין מרבין עליו ואין מדקדקין עליו – we don’t give him too much information, and are not too pedantic.” The Shach explains that we do not want to scare him too much with too many detailed rules and halachot. If he accepts these details, we move onto the next stage.
- The next stage does not appear in the baraita, but is added by the Rambam and the Shulchan Aruch that we now educate him with the principles and basics of Judaism, which are believing in the uniqueness of Hashem and the prohibition of idol worship.
- The next stage is performing circumcision.
- After he has healed from the circumcision, he “immediately” immerses in the mikveh.
- While in the mikveh, two sages inform him of the mitzvot again. Rashi explains the purpose of this second informal of mitzvot as being that since the immersion completes the conversion process, he needs to accept the yoke of mitzvot at this point.
The Need for Three Dayanim
The Gemara relates the following case:
There was an incident in the house of Rabbi Chiyya bar Rabbi… in which a convert came before him who was circumcised but had not immersed. He said to the convert: Remain here with us until tomorrow, and then we will immerse you.
Rabba said: Learn from this incident three principles: Learn from it that a convert requires a court of three people to preside over the conversion, as Rav Safra taught that the case involved three Sages. And learn from it that one is not considered to be a convert until he has been both circumcised and immersed. And learn from it that the court may not immerse a convert at night, as they instructed him to remain there until the following day…. Rabbi Chiyya bar Abba said that Rabbi Yochanan said: A convert requires a court of three to preside over conversion, because “judgment,” is written with regard to him, as the verse states: “And one judgment shall be both for you and for the convert that sojourns with you.”
The Rambam codifies this Gemara as halacha. From this Gemara it is clear that one needs to immerse in a mikveh in front of a Beit Din.
However, the Gemara also cites the following two cases:
There was a certain man whom people would call: Son of the Aramean woman, as they cast aspersions on the validity of his mother’s conversion. With regard to that case, Rav Asi said: Didn’t she immerse for the sake of purifying herself from her menstruation? A similar incident is recounted: There was a certain man whom people would call: Son of an Aramean man, as they cast aspersions on the validity of his father’s conversion. Rabbi Yehoshua ben Levi said: Didn’t he immerse for the sake of purifying himself from his seminal emission? That intention is sufficient to consider the immersion an immersion for the sake of conversion.
These two stories show that the Amoraim understood that a woman immersing in the mikveh for nidda purposes or a man immersing for seminal discharge purposes (tumat keri) are considered sufficient immersions for the conversion process. Some commentators explain that if someone immerses for the purpose of nidda or a seminal discharge, that itself indicates that they conduct themselves as Jews and accepted the yoke of mitzvot; hence, the immersion is considered valid.
These two stories seem to be a glaring contradiction to the Gemara mentioned previously – if we learned in the first case that three dayanim must witness the immersion for it to be considered valid, how can the Amoraim in the second case consider an immersion without three dayanim as valid? Even if one assumes the immersion for seminal discharge was done in front of three people, immersion by a woman for purification from nidda status is definitely done in private. How, then, could Rav Asi validate this immersion for conversion?
Tosafot explain that we must distinguish between the different stages of conversion. Although three dayanim are needed for the conversion, not all stages are equal in terms of the need for the presence of beit din. When one accepts the yoke of mitzvot upon himself, this has to be done in front of three dayanim, even post facto, and without this, the conversion is not valid. On the other hand, regarding immersion and brit mila, even though three dayanim are required, if they were not present, the conversion is valid. The Rosh also quotes this distinction and adds another explanation: Since the entire world knows that that woman immersed for nidda purposes, כאילו עומדין שם דמי, “it is considered as if the beit din were present.” In other words, if an immersion where three dayanim were not present was nevertheless known to the public, it would still be considered valid.
Tosafot and the Rosh mention another contradiction: The Gemara states that one cannot immerse for conversion at night, as the court does not sit at night. Yet, a woman must immerse for nidda purposes at night, so how could Rav Asi consider her immersion as valid for conversion? One answer given by the Rosh in the name of Rabbeinu Meir is that just as the need for three dayanim to witness the immersion is only lechatchila, but bedi’eved (post facto) the immersion is valid, the same is true with regard to immersion at night: Bedi’eved, it is still valid. The Rosh himself suggests a different answer, namely that the conversion process is a long process that starts with acceptance of the mitzvot and ends with the immersion. Once the acceptance of mitzvot was done by day, it is considered as if the entire process started by day and continued into the night. Indeed, the halacha is that if a court first sat during the day and the discussions need to be continued, it is permissible to do so at night.
The Rif takes a different approach. According to him, the Amoraim did not consider immersion for purification from a seminal discharge or from nidda status as a valid immersion for conversion. Rather, their claim was that if we see people acting as Torah-observant Jews, we have no reason to suspect that there was something invalid in their conversion process. In the words of the Magid Mishneh, “היכי קאמרינן שלא נתגיירו כראוי? – “how can we say that they did not convert according to halacha,” when they are performing all mitzvot just like other Jews? According to the Rif, one always needs three dayanim to witness the immersion, even bedi’eved.
However, in truth the opinion of the Rif is slightly more nuanced than this, as he states that if until now we have regarded the descendants of a convert as Jews and now rumors and doubts begin to circulate as to whether his father’s conversion was valid, this is not sufficient to start treating him as if he is not Jewish. Regarding the father, though, as long as there is no certainty that the immersion was performed before three dayanim, we don’t permit him to marry.
The following points emerge according to the opinion of the Rif:
- Three dayanim must be present at all stages of the conversion, and their absence invalidates the conversion, even bedi’eved.
- Whoever had children and rumors were later spread about him that his immersion for conversion did not take place in front of three dayanim, although he is prohibited from marrying, we do not invalidate his descendants nor consider them illegitimate. Rather, they remain valid Jews, as they were considered until now.
The Tur first cites the opinion of his father, the Rosh, and then that of the Rif. The Shulchan Aruch writes16 that “all conversion matters” must be performed before three dayanim and during the day, like all other legal matters, but this is only lechatchila (ideally). Bedi’eved, if a convert underwent circumcision with two witnesses at night, or immersed for purposes other than conversion, (such as קרי for a man or nidda for a woman), s/he is considered a Jew and may marry within Am Yisrael, but when accepting mitzvot, three dayanim are required, even post facto. The Turei Zahav explains that the reason for the requirement of three dayanim for the kabalat mitzvot even bedi’eved is that “זהו גוף הדבר והתחלתו – this is its essence [of conversion] and the beginning of everything.”
It is clear that the distinction of the Shulchan Aruch between different aspects of the conversion process is in accordance with the opinion of Tosafot mentioned earlier. But the Shulchan Aruch then writes that according to the Rif and Rambam, as long as the convert has not yet had children with a Jewish woman, he must repeat all the stages before three dayanim, including the circumcision and immersion. Only in the case where he had children is his conversion valid, in order to ensure that the children’s Jewish status is not questioned.
The Acharonim explain that although the child would be Jewish in any event (as the mother is Jewish), there could be practical ramifications regarding the children being able to marry kohanim and other ramifications.
Are the Dayanim Representatives of Klal Yisrael or of Hashem?
We have seen that beit din is needed for the conversion process, but there is a machloket Rishonim as to which part of the process is critical that they be present at and without their presence invalidates the conversion. However, it is not clear why the Torah demanded that a beit din is needed in the first place. Some Acharonim explain that the entire process of conversion follows the process that took place at Har Sinai. At Har Sinai when the Jewish people accepted the Torah, the Shechina was present. The beit din fulfills the role of representing Hashem, who accepts him as a convert. The Beit Halevi agrees that the beit din represents Hashem, but explains the requirement differently. Conversion in essence is entering into a covenant and in order for it to be valid, both parties have to be present. Therefore, the beit din represent Hashem, who is the other party at the entering of the covenant.
On the other hand, Rav Shaul Yisraeli posits that the beit din act as representatives of Klal Yisrael, who accept the convert as part of the nation. Based on his understanding, Rav Yisraeli answers a challenging question on the opinion of Tosafot. As we mentioned above, Tosafot hold that of the three elements of conversion, acceptance of mitzvot, and brit mila and immersion, only the acceptance of mitzvot needs to be done in front of the dayanim. But this stage happens at the beginning of the process, as we saw in the baraita quoted above. Logic would dictate that if the beit din’s presence is critical, surely they should be present at the final stage when the conversion actually takes effect? Rav Yisraeli answers that the beit din are present at the beginning in order for Am Yisrael to give permission for the gentile to start the conversion process.
The question of whether the beit din represent Am Yisrael or Hashem may have far reaching implications regarding the nature of kabalat ol mitzvot, the acceptance of mitzvot, an issue that we will touch on in the second part of this article.
 Masechet Yevamot 47a
 Rav Shmuel Eliyahu, chief rabbi of Tzefat and son of Rav Mordechai Eliyahu, stated in a shiur that in every generation, one must find the shortcomings of the Jews at that time and emphasize them to the gentile during the first stage of conversion. That is why in our days, potential converts in Israel should be informed that they would have to send their sons to the army with all the inherent dangers, etc.
 Yoreh Deah 288:5
 Hilchot Issurei Biah 14:2
 Yoreh Deah 288:2
 The Maharsha questions why he would be taught about the prohibition of idol worship in order to convert, as even gentiles are forbidden to engage in idol worship.
 The Gemara later clarifies that it should say three talmidei chachamim, as this constitutes a beit din.
 Masechet Yevamot 46b
 Hilchot Issurei Biah 13:7
 Tosafot (s.v. ein) explain further that the convert could not immerse at night even though he had already had a brit mila. One might have thought that since he already started the conversion process through the brit, the immersion should be considered as if it is concluding the court ruling, and the halacha is that although a beit din cannot start the court proceedings at night, it may in certain cases conclude them. Tosafot explain that this is not the case here, as the Gemara views the immersion as if it is the beginning of the court ruling.
 Masechet Yevamot 45b
 Masechet Yevamot 45b, s.v.מי
 Rosh, Yevamot 4:31
 Masechet Sanhedrin 32a
 Yevamot 15b, pagination of the Rif
 Hilchot Issurei Biah 13:9
 Yoreh Deah 268:9
 See Masechet Keritut 9a
 See Yeshuot Yisrael, Choshen Mishpat 3
 Beit Halevi on the Torah, Parshat Lech Lecha, s.v. B’midrash Rabba
 Chavat Binyamin pp. 409-412