פרו ורבו Understanding the Mitsvah to be Fruitful and Multiply

MISHNA: A man may not neglect the mitzva to be fruitful and multiply unless he already has children. Beit Shammai say: One fulfills this mitzva with two males, and Beit Hillel say: A male and a female, as it is stated: “Male and female He created them” (Genesis 5:2).

§ The mishna states that Beit Shammai say that one fulfills the mitzva to be fruitful and multiply when he has two males. The Gemara asks: What is the reason of Beit Shammai? The Gemara answers: We learn this from Moses as it is written: “The sons of Moses, Gershom and Eliezer” (I Chronicles 23:15). Since Moses did not have any other children, two sons must be sufficient to fulfill the mitzva. And the reason of Beit Hillel is that we learn from the creation of the world, as mankind was created male and female. The Gemara asks: And Beit Shammai, let them learn from the creation of the world as well. The Gemara answers that Beit Shammai could say to you: We do not derive a case where it is possible from one that is not possible. Mankind was initially created with a male and female because otherwise reproduction would not have been possible. However, this fact cannot serve as a source that the mitzva to be fruitful and multiply is fulfilled only once one has a son and a daughter. The Gemara asks: And Beit Hillel, let them also learn from Moses. Beit Hillel could say to you: Moses acted based on his own perception when he separated from his wife, but this does not mean that a man is permitted to neglect the mitzva to be fruitful and multiply after fathering two males, as it is taught in a baraita: Moses did three things based on his own perception, and his perception agreed with the perception of the Omnipresent: He separated from his wife, he broke the tablets, and he added one day to the days of separation before the revelation at Sinai. The Gemara clarifies: When Moses separated from his wife after the revelation at Sinai, what did he interpret that led him to do so? He said: If in the case of Israel, with whom the Divine Presence spoke only temporarily and for whom God set a specific time for revelation, the Torah stated: “Do not approach a woman” (Exodus 19:15), I, Moses, who am set aside for divine speech all the time and for whom God did not set a specific time, all the more so I must separate from my wife. And his perception agreed with the perception of the Omnipresent, as it is stated after the revelation at Sinai: “Go say to them: Return to your tents; and you, stand here with Me” (Deuteronomy 5:26–27). This indicates that whereas others could return to their homes and normal married life after the revelation at Sinai, Moses was to stay with God and not return to his wife. Moses broke the tablets following the sin of the Golden Calf. What did he interpret that led him to do so? Moses said: If in the case of the Paschal lamb, which is only one of 613 mitzvot, the Torah states: “No alien shall eat of it” (Exodus 12:43), excluding not only gentiles but apostate Jews as well, then here, in the case of the Golden Calf, where the tablets represent the entire Torah and where the Jewish people are apostates, as they are worshipping the calf, all the more so must they be excluded from receiving them. And his perception agreed with the perception of the Omnipresent, as it is written: “The first tablets that you broke [asher shibbarta]” (Exodus 34:1), and Reish Lakish said: The word asher is an allusion to the fact that the Holy One, Blessed be He, said to Moses: May your strength be true [yishar koḥakha] that you broke the tablets. When Moses added one day to the days of separation before the revelation at Sinai based on his own perception, what did he interpret that led him to do so? He reasoned that since it is written: “And sanctify them today and tomorrow” (Exodus 19:10), the juxtaposition of the words “today” and “tomorrow” teaches that today is like tomorrow: Just as tomorrow the men and women will separate for that day and the night preceding it, so too, today requires separation for the day and the night preceding it. Since God spoke to him in the morning, and the night of that day already passed, Moses said: Conclude from this that separation must be in effect for two days aside from now, i.e., not including the day of the command. Therefore, he extended the mitzva of separation by one day. And his perception agreed with the perception of the Omnipresent, as the Divine Presence did not rest upon Mount Sinai until Shabbat morning, as Moses had determined. § It is taught in a baraita that Rabbi Natan says that Beit Shammai say: The mitzva to be fruitful and multiply is fulfilled with two males and two females. And Beit Hillel say: A male and a female. Rav Huna said: What is the reason of Rabbi Natan, in accordance with the opinion of Beit Shammai? It is as it is written: “And again she bore his brother [et aḥiv] Abel [et Hevel]” (Genesis 4:2). The use of the superfluous word “et” indicates that she gave birth to Abel and his sister, in addition to Cain and his sister. And it states: “For God has appointed me another seed instead of Abel; for Cain slew him” (Genesis 4:25). This indicates that one must have at least four children. And the Rabbis, how do they understand this verse? In their opinion, Eve was thanking God for granting her another child, but one is not obligated to have four children. It is taught in another baraita that Rabbi Natan says that Beit Shammai say: The mitzva to be fruitful and multiply is fulfilled with a male and a female. And Beit Hillel say: Either a male or a female. Rava said: What is the reason of Rabbi Natan in accordance with the opinion of Beit Hillel? It is as it is stated: “He did not create it a waste; He formed it to be inhabited” (Isaiah 45:18), and one has made the earth inhabited to a greater degree by adding even one child to the world.