משנה אויף בראשית 1:28

And these [vows] are not binding: [One who says] “What I eat of yours shall be unconsecrated”; “As the flesh of the swine”; “As an object of idolatrous worship”; “As hides pierced at the heart”; “As carrion”; “As terefoth”; “As abominations”; “As creeping things”; “As Aaron’s dough”; “As his terumah”--[in all these cases the vow is] not binding. If one says to his wife, “Behold! You are like my mother to me”, he must be given an opening on other grounds, in order that he should not act lightly in such matters. [If one says,] “Konam if I sleep”; “If I speak”; or “If I walk”; or if one says to his wife, “Konam if I cohabit with you,” he is liable to [the biblical prohibition] “he shall not break his word” (Numbers 30:. [If he says,] “I swear] an oath not to sleep”, or, “talk,” or, “walk,” he is forbidden [to do so].

A man shall not abstain from procreation unless he already has children. Beth Shammai says: two males, And Beth Hillel says: male and a female, for it says, “Male and female created he them” (Genesis 5:2). If a man married a woman and lived with her for ten years and she bore no child, he may not abstain [any longer from the duty of propagation]. If he divorced her she is permitted to marry another, and the second husband may also live with her for ten years. If she miscarried [the period of ten years] is counted from the time of her miscarriage. A man is commanded concerning the duty of propagation but not a woman. Rabbi Yohanan ben Beroka says: Concerning both of them it is said, “And God blessed them; and said to them… “Be fruitful and multiply” (Genesis 1:28).