And the LORD said, “What have you done? The voice of your brother’s blood is crying to me from the ground.
10. What hast thou done ? The voice of thy brother’s blood Moses shows that Cain gained nothing by his tergiversation. God first inquired where his brother was; he now more closely urges him, in order to extort an unwilling confession of his guilt; for in no racks or tortures of any kind is there so much force to constrain evildoers, as there was efficacy...
We have here a full account of the trial and condemnation of the first murderer. Civil courts of judicature not being yet erected for this purpose, as they were afterwards (Gen 9:6), God himself sits Judge; for he is the God to whom vengeance belongs, and who will be sure to make inquisition for blood, especially the blood of saints. Observe, I.
Commenting on Genesis 4:9-12
And now art thou cursed from the earth,.... From receiving benefit by it, and enjoying the fruits of it as before, and from having a settled dwelling in it, as is afterwards explained: which hath opened her mouth to receive thy brother's blood from thy hand; the blood of his brother, which was shed by his own hand, was received and sucked into the earth...