Não se pode desistir da mitzvá da procriação, a menos que ele tenha filhos. Beth Shammai diz: Dois homens, [derivados de Moisés, que se separaram de sua esposa depois que ele gerou dois homens.] E Beth Hillel diz: Um homem e uma mulher, que estão sendo escritos (Gênesis 1:27): "Homem e fêmea Ele os criou. " [E Moisés não pode servir como um precedente, pois agiu por decreto divino.] Se alguém se casou com uma mulher e viveu com ela dez anos sem ter filhos, ele não pode desistir (da mitzvá). [Como encontramos com Abraão. Depois de viver com Sarah por dez anos e não ter filhos, ele se casou com Hagar. O tempo que ele morou com ela fora de Eretz Yisrael não está incluído, pois morar fora da terra pode ter contribuído (para a falta de filhos). E todo o tempo em que um homem ou uma mulher está doente, ou encarcerado, ou em qualquer outro estado em que a coabitação seja impedida, isso não é incluído no período de dez anos.] Se ele se divorciar dela, ela poderá se casar com outro. [Por isso (a falta de filhos) pode ser devida não a ela, mas a ele. E quando ele se divorcia dela, ele lhe dá (a quantidade de) seu kethubah, se ela afirma que isso se deve ao fato de ele "não atirar como uma flecha". E lhe impomos uma proibição se ela souber o contrário e fizer uma alegação falsa contra ele.] É permitido ao segundo viver dez anos com ela. E se ela abortar, ele conta a partir do momento em que ela abortar. A mitzvá de gerar filhos recai sobre o homem e não sobre a mulher [que está sendo escrita (Gênesis 1:27): "Seja frutífero e multiplique ... e submeta-o" ("vekivshuhah"). Está escrito com defeito, sem o vav após o shin (implicando que apenas um está sendo abordado e que a mitzvá da procriação recai sobre o homem, o "subjugador" da mulher.)] R. Yochanan b. B'roka disse: De ambos (homem e mulher) está escrito (Ibid. 28): "E D'us os abençoou, e D'us lhes disse: 'Sejam frutíferos e multipliquem.'" [A halachá não está de acordo com ele.]
Shadal
And he blessed them: He gave them the power and setup for all of this; and He also said to them, "be fruitful and multiply, etc.," which is to say that He explained to them what their power and nature [consists of] and what He wants from them. And above (verse 22) with the fish and the birds, it did not say "And God said to them," since they are not intelligent creatures. And behold, to man - when the human species was at the beginning of its existence, and so [too] below (Genesis 9:1,7) when the human specie was very little - He explained His desire, that they be fruitful and multiply and fill the earth. And when He gave the Torah to Israel, it was not necessary to command them about this, since the earth was already settled. And nonetheless, the Sages, of blessed memory, did well when they counted (Yevamot 6:6), "be fruitful and multiply" as one of the [Torah's] commandments; since it is certainly the will of God that the human species [continue] to be fruitful and multiply. And especially after the destruction [of the Temple] when the [Jewish] people had decreased, they needed to reinforce this commandment. And 'blessed is He that chose them and their teachings;' since were it not for their prohibitions and their decrees, the nation would have been lost from the world, [just] like several great and powerful nations were lost and forgotten.
ויברך..פרו ורבו, the word הפריה describes the fertilisation, leading up to birth; the word רביה refers to the quantitative development of such offspring. Even though, in the first instance this is a blessing, just as it is in verse 22 when G’d blessed the fish, our sages in Yevamot 65 and in Bereshit Rabbah 8,12 understand this verse as a commandment to the human race to reproduce. They say: “man is command to practice this commandment, whereas for woman it is not an active commandment.” Although the commandment was addressed to man in the plural mode,פרו ורבו, encouraging us to think that the commandment applies to males and females equally, this is not so. As far as the blessing contained in this verse is concerned, it applies to both males and females; the commandment part applies only to the males, and is based on the singular mode in the word וכבשה where the missing letter ו which would have made this a plural mode indicates to our sages that as a directive the whole verse is applicable only to the males of the species. They use psychology to arrive at this conclusion, saying that it is in the nature of the male to engage in conquest, כבוש, not in the mature of the females of the species. Even though this matter is the subject of some disagreement among the sages, (on that folio in Yevamot), the halachah has been decided according to the view that only the male is obligated to fulfill the commandment to have children. The defective spelling of the word וכבשה without the letter ו in the middle, gives rise to additional halachic points, such as that it is not the nature of a woman to go out into the public marketplace, and that the male is to be the instigator of marital intercourse and not his wife. (Bereshit Rabbah 8,12)