Jamieson, Fausset and Brown on Leviticus 2:14

14. a meat offering of thy first-fruits--From the mention of "green ears," this seems to have been a voluntary offering before the harvest--the ears being prepared in the favorite way of Eastern people, by parching them at the fire, and then beating them out for use. It was designed to be an early tribute of pious thankfulness for the earth's increase, and it was offered according to the usual directions.