Genesis 4:5

Cain was very wroth, and his countenance fell— Cain's jealousy and envy of his brother filled his heart with anger and indignation against him, passions which immediately discovered themselves in his gloomy, downcast, and revengeful countenance. Upon which the Lord condescends to expostulate with him; "Why art thou wroth, and why is thy countenance fallen? what reasonable and just ground is there for thy jealousy, envy, and anger? If thou hadst done well (sacrificed as thou oughtedst) shouldest thou not have been accepted? for thou servest a God who is no respecter of persons, but a just rewarder of men according to their works: as therefore thou mayest certainly expect his favour on doing well; so, if thou doest not well; a sin-offering lieth at the door of the fold; so the original word signifies. Be at rest, רבצ, robetz, and unto thee shall be his (thy brother's) desire, and thou shalt rule over him. He is still thy younger brother, and shall be subject to thee. Thou shalt still retain the privilege of thy birth-right, and needest not be jealous or envious of thy brother, who shall continue in the due subjection of a younger brother to thee."

REFLECTIONS.—The sons of Adam no sooner were grown up for labour, but we find them before the Lord. Religion was the first thing, no doubt, he taught them, and divine worship is a principal part of it.

1. They appeared, according to their vocations, with their respective offerings of the fruit of the ground and of the flock. According as the Lord hath blessed us, we are bound to honour him with our substance, whether for the support of his cause, or the relief of the distressed. He will count this done to himself. But among the worshippers of God there will ever be found hypocrites: men forward enough to bow the knee, and give alms, and appear religious, but void of true faith. Such was Cain.
2. In consequence, Cain's offering was rejected, whilst Abel's was accepted. But what was the effect upon Cain? Anger against God, as if he were unjust in his regards; and envy at his innocent brother, because of God's favour to him, kindle in his bosom, dart from his fiery eyes, or disfigure his pale and fallen countenance. Behold a lively picture of the devil: how like is the offspring to the parent; a fallen man to a fallen angel?
3. The children of God are ever the objects of anger and envy to the children of this world.
4. God condescends to reason with Cain on the perverseness of his conduct. The sinner that perishes, shall be left inexcusable. It were well, if on the first motions of sin in the heart, or on the first glance of the kindling eye, this question were in our thoughts, Why art thou wroth? There was no reason for it: for acceptance was as free for him as for his brother, if he came in the same way: it was infidelity and disobedience only that excluded him; but the moment he returned, he would have found favour: if he had brought the sacrifice of faith, it would have been welcome; for God is ever ready to receive the returning sinner. O may his goodness lead us to repentance!
5. Many were the aggravations of Cain's foul crime. It was his brother whom he slew; a brother to him ever dutiful and submissive, a person distinguished with God's favour, and one who, unsuspicious of danger, talked with him as a friend. But what can stand before malicious envy? No doubt the time was, when Cain would have started at the horrid deed; but when once a man gives place to the devil, there is no conception to what a pitch of daring wickedness he may arrive. Obsta principiis. Watch the first risings of sin; and if you would not commit murder, refrain from anger.