And in process of time it came to pass, that Cain brought of the fruit of the ground an offering unto the LORD. In process of time - מקץ ימים mikkets yamim, at the end of days. Some think the anniversary of the creation to be here intended; it is more probable that it means the Sabbath, on which Adam and his family undoubtedly offered oblations to God, as the Divine worship was certainly instituted, and no doubt the Sabbath properly observed in that family. This worship was, in its original institution, very simple. It appears to have consisted of two parts:
1. Thanksgiving to God as the author and dispenser of all the bounties of nature, and oblations indicative of that gratitude.
2. Piacular sacrifices to his justice and holiness, implying a conviction of their own sinfulness, confession of transgression, and faith in the promised Deliverer. If we collate the passage here with the apostle's allusion to it, Hebrews 11:4, we shall see cause to form this conclusion.
Cain brought of the fruit of the ground an offering - מנחה minchah, unto the Lord. The word minchah is explained, Leviticus 2:1, etc., to be an offering of fine flour, with oil and frankincense. It was in general a eucharistic or gratitude offering, and is simply what is implied in the fruits of the ground brought by Cain to the Lord, by which he testified his belief in him as the Lord of the universe, and the dispenser of secular blessings.