Q. BS”D, Hello Rabbi Bartfeld, my question is why didn’t Adam punish and chastise Cain for
slaying Abel? Usually it’s the parents that mete out punishment. And also, why did Adam
and Eve wait 130 years to have Seth? Thank you. Have a nice day and Shabbat Shalom.

A. In this particular first case, since Hashem directly and immediately punished Cain, Adam’s chastising was likely unnecessary. Further, Adam, as can be gleaned from various medroshim, was deeply in mourning and in sorrow for having committed the sin that expelled mankind from Gan Eden and brought death to all in this world. Adam’s unrighteousness was far greater, more critical and everlasting than Cain’s. How would he then have the moral strength to rebuke Cain.
Rashi mentions (Bereshis 4: 25, 5: 3) that Adam separated himself from his wife, due to his deep feelings of guilt as mentioned above. It was only after Lemech intervened that he rejoined Chava and that happened after 130 years.

Rabbi A. Bartfeld