Summary: A bloodless offering - offered by those already covered by the Blood.
THE GRAIN OFFERING
It might be appropriate at this point to consider the significance of the “grain offering” (Leviticus 2). This was a voluntary offering - literally, “a gift” - and Hebrew scholars generally understand that it was offered along with one of the other offerings. Perhaps the difference between Cain and those who made the bloodless offering of Leviticus 2 was that they were already “covered” by the blood. But what is important is the ATTITUDE OF GRATITUDE in which the offering was made (Psalm 96:8).
The grain offering was made with oil, representing the Holy Spirit (Zechariah 4:1-6). There was also salt to purify (2 Kings 2:19-22), symbolic of our covenant bonding with God (Numbers 18:19). And finally incense, to make “AN AROMA PLEASING TO THE LORD.”
This fragrance is like the “odour” which permeated the house where Mary, at great expense to herself, anointed the feet of Jesus (John 12:3). It contrasts with the grudging gift of Ananias and Sapphira (Acts 5:1-4).