The Mitzvah to Have Children
Genesis 1:28 (according to some opinions, 9:7), is the source for the Torah commandment to “be fruitful and multiply,” known as periya u-rviya. Halacha defines this Torah-level commandment as having one son and one daughter, who themselves can reproduce. Technically, this mitzvah applies to men and not to women. Now that a man may have only one wife, a woman becomes an essential partner in enabling her husband to fulfill the commandment.
Women also may be obligated in the rabbinic-level mitzva of shevet, inhabiting the world. Shevet derives from Isaiah 45:18, “He did not create it a waste; He formed it for habitation [shevet],” and entails having at least one child.
There is also a rabbinic admonishment, la-erev, to continue to procreate even after fulfilling the quota mandated by the Torah. It is expounded from the verse in Ecclesiastes 11:6, “In the morning sow your seed, and in the evening [la-erev] do not desist.”
Some authorities consider la-erev to be obligatory, while others see it as an encouragement with potential mitzva fulfillment, but not a strict requirement. Our founding rabbinic supervisor, Rav Yehuda Henkin z”l, considered a couple to have fulfilled both periya ur-viya and la-erev with a total of two boys and two girls.
Reasons to Permit Contraception
Although there is a Torah commandment to have children, and although Jewish law strongly encourages families larger than the minimum size, contraception is permitted, or even required, under certain circumstances.
A woman whose life would be endangered by pregnancy or childbirth is required to use birth control, in accordance with the principle that all commandments (except for the prohibitions against adultery/incest, idolatry, and murder) are suspended where life is in danger.
Other situations, including the woman’s physical or mental health and the family’s ability to cope, may also be grounds for allowing contraception. Many authorities permit spacing of births as well.
Please see here for a summary of the rulings of our founding rabbinic supervisor, Rav Yehuda Henkin z”l, on the topic of family planning. Couples are encouraged to consult a halachic authority for personal guidance regarding contraception.
Updated November 2021.