John Gills Exposition of the Bible Commentary - Genesis 4:4
And Abel, he also brought of the firstlings of his flock ,.... As he was a shepherd, his flock consisted of sheep; and of the firstlings of these, the lambs that were first brought forth, he presented as an offering to the Lord; and which were afterwards frequently used in sacrifice, and were a proper type of Christ, Jehovah's firstborn, the Lamb of God that takes away the sin of the world, a Lamb without spot and blemish; fitly signified by one for his innocence, harmlessness, and meekness:... read more
Matthew Henry's Complete Commentary - Genesis 4:3-5
Here we have, I. The devotions of Cain and Abel. In process of time, when they had made some improvement in their respective callings (Heb. At the end of days, either at the end of the year, when they kept their feast of in-gathering or perhaps an annual fast in remembrance of the fall, or at the end of the days of the week, the seventh day, which was the sabbath)--at some set time, Cain and Abel brought to Adam, as the priest of the family, each of them an offering to the Lord, for the doing... read more