John Gills Exposition of the Bible Commentary - Genesis 4:5
But unto Cain and to his offering he had not respect ,.... Not because of the matter of it, as some have thought; but because it was not offered in faith and sincerity, but in a formal and hypocritical manner, without any regard to the Messiah and his sacrifice, and without any view to the glory of God: no notice was taken, no approbation was given of it by the above token, or any other; so that it was manifest to Cain himself, that God did not approve of it, or was well pleased with it, as... 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