“And Cain said unto the Lord, My punishment is greater than I can bear.” In sadness and darkness and terror did the unhappy wretch set out upon his wanderings. Yet not in solitude. Even in this punishment, God had mercy; He gave Cain human companionship to soften and sustain him. The Bible makes no positive statement of any daughters born thus early to Eve; but Hebrew legends mention them, and the Scripture leaves us to assume them. For presently it speaks of Cain’s wife as accompanying him, and then of a son and grandsons gathering around the pair.
The little party fled from the more fertile regions of earth. Part of the curse upon Cain had been that when he tilled the ground he should get but little return in crops. This implies that his journeying was through a barren land. Hence the artist has here pictured Cain with fear fixed forever on his brow, leading his unhappy band through a wilderness, that dark and mysterious “land of Nod” wherein the Bible tells us that he dwelled.”
The Bible and its Story, Volume 1: The Law, Genesis to Leviticus
Bewer, Julius; Horne, Charles