And the LORD said unto Cain, Where is Abel thy brother? And he said, I know not: Am I my brother's keeper?
Where is Abel thy brother? When Cain saw the fatal result of his attack on his brother, he would anxiously endeavour to conceal all traces of his crime by burying the corpse somewhere under ground; and we can easily conceive of him pretending ignorance of what had become of Abel, so far as to join in the search that doubtless would be instituted regarding the missing relative. It might be that a considerable time had elapsed ere the following scene took place; and Cain had probably, in order to lull suspicion, been engaging in the solemnities of religion at the established place of worship, when he was challenged directly from the Shechinah itself.
I know not - `I have not ascertained' (Murphy). This was a direct and unblushing falsehood, and hence, Cain is said to be of the wicked one (1 John 3:12), who was a liar and a murderer (John 8:44). What a difference between Adam and Eve in their simple, trembling confession of the sin they had committed, and the hardened audacity of their oldest son! One sin leads to another; and a criminal, when accused, commonly tries to evade the consequences of his guilt by denial. Thus acted Cain; but from the irreverent, defiant tone he assumed, we may judge the extent of his inward apostasy from God, and the spiritual blindness of his understanding, which deluded him into the belief that he could escape the scrutiny of Omniscience.