Halakha Ulangan 23:3: Mishneh Torah, Marriage, Gray Matter II, Mishneh Torah, Forbidden Intercourse & Gray Matter I

Intercourse prohibitions according to the Torah for which there is no punishment of karet are called “negative prohibitions”. They are also called “holy prohibitions”. There are nine [such prohibitions] and they are: a widow to a high priest, a divorced woman or zona or ḥalala to a high priest or to an ordinary priest, a mamzeret to an Israelite man, an Israelite woman to a mamzer, an Israelite woman to an Ammonite or Moabite man, an Israelite woman to one with crushed [genitals], or severed [genitals], one’s ex-wife after she has remarried, one’s yevama who married a stranger while still under the yavam’s control. A ḥalutza is like a divorced woman and is forbidden to a priest according to Rabbinic law. The Gibeonites are like mamzerim, whether male or female, and they are prohibited according to Rabbinic law. The Gibeonites will be explained in the Laws of Forbidden Intercourse.

Although most authorities do not fundamentally object to IVF, at least for married couples, several major problems do arise during IVF procedures,⁸See Rav Asher Weiss’s and Rav Gidon Weitzman’s essays in Techumin (23:220-230) regarding the performance of IVF-related procedures on Shabbat. Rav Weiss rules that the halachic status of choleh she’ein bo sakanah (victim of a non-life-threatening illness) applies to the couple (which entails certain leniencies, as we discussed in an earlier chapter), and Rav Weitzman cites many other authorities who share this view. Nevertheless, Rav Weiss notes that in practice, it is always preferable to perform all necessary procedures during the week, as halachic questions can arise during every step of a procedure on Shabbat. including procuring the husband’s sperm in a halachically acceptable manner, the permissibility of paying a woman to donate an ovum (if one’s Rav permits using a donated ovum), and concern for the possible mamzeirut (illegitimate status) of the donor (if permitted),⁹Concern for mamzeirut (described in the Sifrei’s comments to Devarim 23:3) could arise if we were to worry that the donor is a Jew born from an illicit relationship (other than nidah) punishable by kareit (such as adultery or incest). Rav Zalman Nechemia Goldberg, Rav David Feinstein, and Rav J. David Bleich all told me (in 1991) that we generally need not worry about this problem when doing IVF (see Techumin 10:281), as the majority of donors (rov) are not mamzeirim. Nevertheless, if we know for sure that a particular donor was a mamzeir, the resulting child would presumably also be a mamzeir (see Tzitz Eliezer 15:45). Rav Moshe Feinstein (Teshuvot Igrot Moshe, Even Ha’ezer 3:11) claims, however, that a man cannot transmit mamzeirut to children whom he fathers without a sexual act. Accordingly, were a mamzeir to donate sperm for IVF, the child would not be a mamzeir. However, other authorities give no indication of accepting Rav Moshe’s opinion. and the credibility of a non-observant or non-Jewish doctor’s assertion that he used the sperm and/or ovum of a particular person.

1. What is meant by the Torah's prohibition (Deut. 23:3) against relations with a mamzer? [The term refers to a person conceived from] a forbidden sexual relationship. A niddah is an exception. A son conceived from such relationships is blemished, but is not a mamzer. When, however, a man enters into any other forbidden sexual relationships, whether through rape, or willingly, whether conscious of the prohibition or not, the offspring produced is a mamzer. Both male and female [mamzerim] are forbidden forever, as [Deuteronomy 23:3] states: "[A mamzer shall not enter Gd's congregation.] Also the tenth generation...," i.e., [the prohibition is] everlasting.