פְּרוּ וּרְבוּ Be Fruitful and Multiply

(6) One may not abstain from procreation unless he [already] has children. Beit Shammai say: [One must have] two boys, and Beit Hillel say: [One must have] a boy and a girl, as it says, "Male and female He created them" (Bereishit 5:2).

It is taught in a baraita that Rabbi Eliezer says: Anyone who does not engage in the mitzva to be fruitful and multiply is considered as though he sheds blood, as it is stated: “Whoever sheds the blood of man, by man shall his blood be shed” (Genesis 9:6), and it is written immediately afterward: “And you, be fruitful and multiply” (Genesis 9:7).

Rabbi Ya’akov says: It is as though he diminishes the Divine Image, as it is stated: “For in the image of God He made man” (Genesis 9:6), and it is written immediately afterward: “And you, be fruitful and multiply” (Genesis 9:7).

Ben Azzai says: It is as though he sheds blood and also diminishes the Divine Image, as it is stated: “And you, be fruitful and multiply,” after the verse that alludes to both shedding blood and the Divine Image.

They said to ben Azzai: There is a type of scholar who expounds well and fulfills his own teachings well, and another who fulfills well and does not expound well. But you, who have never married, expound well on the importance of procreation, and yet you do not fulfill well your own teachings. Ben Azzai said to them: What shall I do, as my soul yearns for Torah, and I do not wish to deal with anything else. It is possible for the world to be maintained by others, who are engaged in the mitzva to be fruitful and multiply.