(9) And the Lord said unto Cain, Where is Abel thy brother?--It is the beauty of these early narratives that the dealings of the Deity with mankind are all clothed in an anthropomorphic form, for the reasons of which see Note on Genesis 2:7. It seems, then, that Cain at first went away, scarcely conscious of the greatness of his crime. He had asserted his rights, had suppressed the usurpation of his privileges by the younger son, and if he had used force it was his brother's fault for resisting him. So Jacob afterwards won the birthright by subtilty, and would have paid the same fearful penalty but for timely flight, and rich presents afterwards. But Cain could not quiet his conscience; remorse tracked his footsteps; and when in the household Abel came not, and the question was asked, Where is Abel? the voice of God repeated it in his own heart, Where is Abel, thy brother!--brother still, and offspring of the same womb, even if too prosperous. But the strong-willed man resists. What has he to do with Abel? Is he "his brother's keeper?"

Verse 9. - And the Lord said unto Cain. "Probably soon after the event, at the next time of sacrifice, and at the usual place of offering" (Bonar). Where is Abel thy brother? "A question fitted to go straight to the murderer's conscience, and no less fitted to rouse his wrathful jealousy, as showing how truly Abel was the beloved one" (ibid). Whether spoken by Adam (Luther), or whispered within his breast by the still small voice of conscience, or, as is most probable, uttered from between the cherubim, Cain felt that he was being examined by a Divine voice (Calvin). And (in reply) he said (adding falsehood, effrontery, and even profanity to murder), I know not: am I my brother's keeper? The inquiry neither of ignorance nor of innocence, but the desperate resort of one who felt himself closely tracked by avenging justice and about to be convicted of his crime. "He showeth himself alyer in saying, 'I know not; wicked and profane in thinking he could hide his sin from God; unjust in denying himself to be his brother's keeper; obstinate and desperate in not confessing his sin" (Willet; cf. Psalm 10.).

4:8-15 Malice in the heart ends in murder by the hands. Cain slew Abel, his own brother, his own mother's son, whom he ought to have loved; his younger brother, whom he ought to have protected; a good brother, who had never done him any wrong. What fatal effects were these of our first parents' sin, and how must their hearts have been filled with anguish! Observe the pride, unbelief, and impenitence of Cain. He denies the crime, as if he could conceal it from God. He tries to cover a deliberate murder with a deliberate lie. Murder is a crying sin. Blood calls for blood, the blood of the murdered for the blood of the murderer. Who knows the extent and weight of a Divine curse, how far it reaches, how deep it pierces? Only in Christ are believers saved from it, and inherit the blessing. Cain was cursed from the earth. He found his punishment there where he chose his portion, and set his heart. Every creature is to us what God makes it, a comfort or a cross, a blessing or a curse. The wickedness of the wicked brings a curse upon all they do, and all they have. Cain complains not of his sin, but of his punishment. It shows great hardness of heart to be more concerned about our sufferings than our sins. God has wise and holy ends in prolonging the lives even of very wicked men. It is in vain to inquire what was the mark set upon Cain. It was doubtless known, both as a brand of infamy on Cain, and a token from God that they should not kill him. Abel, being dead, yet speaketh. He tells the heinous guilt of murder, and warns us to stifle the first risings of wrath, and teaches us that persecution must be expected by the righteous. Also, that there is a future state, and an eternal recompence to be enjoyed, through faith in Christ and his atoning sacrifice. And he tells us the excellency of faith in the atoning sacrifice and blood of the Lamb of God. Cain slew his brother, because his own works were evil, and his brother's righteous, 1Jo 3:12. In consequence of the enmity put between the Seed of the woman and the seed of the serpent, the war broke out, which has been waged ever since. In this war we are all concerned, none are neuter; our Captain has declared, He that is not with me is against me. Let us decidedly, yet in meekness, support the cause of truth and righteousness against Satan.And the Lord said unto Cain, where is Abel thy brother?.... Perhaps this was said to him the next time he came to offer, he not being with him: this question is put, not as being ignorant where he was, but in order to bring Cain to a conviction and confession of his sin, to touch his conscience with it, and fill it with remorse for it; and, for the aggravation of it, observes the relation of Abel to him, his brother:

and he said, I know not; which was a downright lie; for he must know where he had left him or laid him: this shows him to be under the influence of Satan, who was a liar, and the father of lies, as well as a murderer from the beginning; and that he was so blinded by him, as to forget whom he was speaking to; that he was the omniscient God, and knew the wickedness he had done, and the falsehood he now delivered, and was capable of confronting him with both, and of inflicting just punishment on him.

Am I my brother's keeper? which was very saucily and impudently spoken: it is not only put by way of interrogation, but of admiration, as Jarchi observes, as wondering at it, that God should put such a question to him, since he knew he had not the charge of his brother, and his brother was at age to take care of himself; and if not, it rather belonged to God and his providence to take care of him, and not to him: so hardened was he in his iniquity, he had stretched out his hand against his brother, and now he stretched it out against God, and ran upon him, even on the thick bosses of his buckler.