And in process of time it came to pass, that Cain brought of the fruit of the ground an offering unto the LORD.
All Commentaries on Genesis 4:3 Go To Genesis 4
John Chrysostom
AD 407
Consider how the Lord of nature added knowledge to conscience. After all, who brought this to our understanding? It was none other than knowledge associated with conscience. The text says, "He brought an offering of the fruits of the earth to the Lord." He knew and understood that he should offer from his own possessions some produce to God as to his master. not because God needs them, but for the purpose of demonstrating his gratitude as being himself a beneficiary of such kindness. God, you see, is proof against need, and depends on nothing we have to offer; but in his ineffable love he shows considerateness for us, and for the sake of our salvation he allows these things to happen so that knowledge of the Lord may be for the human race a school of virtue.