Commandment 57 - To Be Fruitful and Multiply

That is that He commanded us to be fruitful and multiply, with the intention of preserving the species. And that is the commandment of piryah verivyah. And that is His, may He be exalted, saying, "And you, be fruitful and multiply" (Genesis 9:7). And they have already explained (Berakhot 16a) that a groom is exempt from the recitation of Shema on account of being busy with [this] commandment. And the laws of this commandment have already been explained in Chapter 7 of Yevamot. But women are not obligated in this commandment. And in the explanation, they said (Yevamot 65b), "A man is commanded to be fruitful and multiply, but not a woman." (See Parashat Bereishit; Mishneh Torah, Marriage 15.)

God blessed them and God said to them, “Be fertile and increase, fill the earth and master it; and rule the fish of the sea, the birds of the sky, and all the living things that creep on earth.”

MISHNA: A man is commanded with regard to the mitzva to be fruitful and multiply, but not a woman. Rabbi Yoḥanan ben Beroka says that a woman is also commanded, as the verse states with regard to both of them: “And God blessed them, and God said to them: Be fruitful and multiply” (Genesis 1:28).

Be fertile, then, and increase; abound on the earth and increase on it.”

The mitzvah of being fruitful and multiplying is incumbent on the husband and not on his wife. When does a man become obligated to fulfill this mitzvah? From the time he reaches seventeen. If he reaches twenty and has not married, he is considered to have transgressed and negated the observance of this positive commandment. If, however, he is occupied with the study of Torah and absorbed in this endeavor and is hesitant of marrying, lest he be forced to work to support his wife and thus be prevented from studying Torah, he is permitted to delay marriage. For a person who is occupied in the performance of one mitzvah is freed from the obligation to perform another. Surely this applies with regard to the study of Torah.

How many children is it necessary for a man to have fathered to be considered to have fulfilled this mitzvah? One boy and one girl, as [implied by Genesis 5:2]: "He created them, a male and a female." If the son was a saris or the daughter an aylonit, he is not considered to have fulfilled this mitzvah.

A man is considered to have fulfilled the mitzvah of being fruitful and multiplying [even when] he fathers [children] and they die, so long as [his children] have left behind children [of their own]. For grandchildren are considered to be children.When does the above apply? When the person's grandchildren are both male and female, and they are descended from a male and a female, even though the male grandchild is the son of the man's daughter, and the female grandchild is the daughter of the man's son. Since they come from two of his children, he is considered to have fulfilled the mitzvah of being fruitful and multiplying. If, however, he had a son and a daughter who both died, and [one did not leave any children, while] one left a son and a daughter, the grandfather is not considered to have fulfilled this mitzvah.

When [a convert] had fathered children as a gentile, and both he and they convert, he is considered to have fulfilled this mitzvah. By contrast, a freed slave who had fathered children as a slave is not considered to have fulfilled this mitzvah, although his children were also freed. Instead, he must father children after he has been freed. [The rationale is that] a slave is not considered to have any paternal lineage.

A man should not marry a barren women, an elderly woman, an aylonit or a minor who is not fit to bear a child unless he has already fulfilled the mitzvah of being fruitful and multiplying, or he has another wife with whom he can father children.When a man has married a woman and remained married to her for ten years without her bearing children, he must divorce her and pay her [the money due her by virtue of her] ketubah, or marry a woman who is fit to bear children.If he does not desire to divorce her, he should be compelled to do so; he should be beaten with a rod until he divorces her. Even when he says, "I will not engage in marital relations with her. Instead, we will dwell together with witnesses so that we will not ever be in private," regardless of whether it is he or she who offers this proposition, it is not accepted. Rather, he is required to divorce [his wife] or marry another woman who is fit to bear children.

Although a man has fulfilled the mitzvah of being fruitful and multiplying, he is bound by a Rabbinic commandment not to refrain from being fruitful and multiplying as long as he is physically potent. For anyone who adds a soul to the Jewish people is considered as if he built an entire world.Similarly, it is a mitzvah of our Sages that a man should not live without a wife, so that he will not be prompted to [sexual] thoughts. Similarly, a woman should not live without a man, so that she will not be suspected [of immoral conduct].