“Lemekh said to his wives, Ada and Tzila: Hear my voice, wives of Lemekh, listen to my speech, for have I slain a man for my wound or a child for my injury?” (Genesis 4:23) “Lemekh said to his wives, Ada and Tzila: Hear my voice.” Rabbi Yosei bar Ḥanina said: He propositioned them for intercourse, but they said to him: ‘Tomorrow the Flood is coming [to destroy all mankind]. Shall we heed you and bring forth children only to be cursed?’
He said to them: ‘“Have I slain a man for my wound,” that wounds should befall me on his account? “[Have I slain] a child for my injury,” that injuries should befall me on his account?’ This was a rhetorical question: Cain committed murder and yet [his punishment] was suspended for him for seven generations;9Genesis 4:15. I, who did not kill anyone, all the more so [punishment] should be suspended for me for that.10For seventy-seven generations (Genesis 4:24).
Hence, you may be assured that no harm will befall your future offspring. Rabbi says: This is a flawed a fortiori argument: If so, from whom would the Holy One blessed be He ever collect His promissory note?11To destroy Cain’s descendants after seven generations. Rabbi Yaakov bar Idi asked before Rabbi Yoḥanan: If “a man,” why “a child”; if “a child,” why “a man”?12Lemekh protested that he, unlike Cain, did not kill a man and a child.
Did Cain kill a man or a child? How could his victim be described with both terms? He said to him: He [Abel] was a man in terms of his limbs,13Abel was fully grown. but a child in terms of years.14Abel lived no more than fifty days (Bereshit Rabba 22:4). He [Lemekh] said to them: ‘Let us go to Adam.’
They went to Adam [for consultation]. He said to them: ‘You do yours and the Holy One blessed be He will do His.’15You must fulfill your duty to procreate, without regard to what God will do later. They said to him: ‘Doctor, heal your own lameness. Have you yourself not separated from Eve for a hundred and thirty years so that you should not produce a son from her?’ This was a rhetorical question. When he heard this, he consorted [with Eve] to produce offspring.