4:1-7 When Cain was born, Eve said, I have gotten a man from the Lord. Perhaps she thought that this was the promised seed. If so, she was wofully disappointed. Abel signifies vanity: when she thought she had the promised seed in Cain, whose name signifies possession, she was so taken up with him that another son was as vanity to her. Observe, each son had a calling. It is the will of God for every one to have something to do in this world. Parents ought to bring up their children to work. Give them a Bible and a calling, said good Mr. Dod, and God be with them. We may believe that God commanded Adam, after the fall, to shed the blood of innocent animals, and after their death to burn part or the whole of their bodies by fire. Thus that punishment which sinners deserve, even the death of the body, and the wrath of God, of which fire is a well-known emblem, and also the sufferings of Christ, were prefigured. Observe that the religious worship of God is no new invention. It was from the beginning; it is the good old way, Jer 6:16. The offerings of Cain and Abel were different. Cain showed a proud, unbelieving heart. Therefore he and his offering were rejected. Abel came as a sinner, and according to God's appointment, by his sacrifice expressing humility, sincerity, and believing obedience. Thus, seeking the benefit of the new covenant of mercy, through the promised Seed, his sacrifice had a token that God accepted it. Abel offered in faith, and Cain did not, Heb 11:4. In all ages there have been two sorts of worshippers, such as Cain and Abel; namely, proud, hardened despisers of the gospel method of salvation, who attempt to please God in ways of their own devising; and humble believers, who draw near to him in the way he has revealed. Cain indulged malignant anger against Abel. He harboured an evil spirit of discontent and rebellion against God. God notices all our sinful passions and discontents. There is not an angry, envious, or fretful look, that escapes his observing eye. The Lord reasoned with this rebellious man; if he came in the right way, he should be accepted. Some understand this as an intimation of mercy. If thou doest not well, sin, that is, the sin-offering, lies at the door, and thou mayest take the benefit of it. The same word signifies sin, and a sacrifice for sin. Though thou hast not done well, yet do not despair; the remedy is at hand. Christ, the great sin-offering, is said to stand at the door, Re 3:20. And those well deserve to perish in their sins, that will not go to the door to ask for the benefit of this sin-offering. God's acceptance of Abel's offering did not change the birthright, and make it his; why then should Cain be so angry? Sinful heats and disquiets vanish before a strict and fair inquiry into the cause.
7. If thou doest well, shalt thou not be accepted?—A better rendering is, "Shalt thou not have the excellency"? which is the true sense of the words referring to the high privileges and authority belonging to the first-born in patriarchal times.
sin lieth at the door—sin, that is, a sin offering—a common meaning of the word in Scripture (as in Ho 4:8; 2Co 5:21; Heb 9:28). The purport of the divine rebuke to Cain was this, "Why art thou angry, as if unjustly treated? If thou doest well (that is, wert innocent and sinless) a thank offering would have been accepted as a token of thy dependence as a creature. But as thou doest not well (that is, art a sinner), a sin offering is necessary, by bringing which thou wouldest have met with acceptance and retained the honors of thy birthright." This language implies that previous instructions had been given as to the mode of worship; Abel offered through faith (Heb 11:4).
unto thee shall be his desire—The high distinction conferred by priority of birth is described (Ge 27:29); and it was Cain's conviction, that this honor had been withdrawn from him, by the rejection of his sacrifice, and conferred on his younger brother—hence the secret flame of jealousy, which kindled into a settled hatred and fell revenge.