Genesis 4:10 - Wesley's Explanatory Notes

And he said, What hast thou done? — Thou thinkest to conceal it, but the evidence against thee is clear and uncontestable, the voice of thy brother's blood crieth — He speaks as if the blood itself were both witness and prosecutor, because God's own knowledge testified against him, and God's own justice demanded satisfaction. The blood is said to cry from the ground, the earth, which is said, Genesis 4:11, to open her mouth to receive his brother's blood from his hand. The earth did as it were blush to see her own face stained with such blood; and therefore opened her mouth to hide that which she could not hinder.