Corn

Boyd’s Bible Dictionary:

Roasted grain
(Ruth 2:14).

Concise Bible Dictionary:

Various Hebrew words are translated “corn,” and usually signify any kind of grain. The “OLD CORN OF THE LAND” was what the Israelites began to eat after crossing the Jordan, when the manna ceased (Josh. 5:11-12). It typifies a heavenly Christ, on whom those feed who have spiritually passed through Jordan—who are experimentally dead and risen with Christ. The manna is rather heavenly grace for wilderness circumstances. In the New Testament Christ speaks of Himself as a “CORN OF WHEAT,” which had to die or it would abide alone: there could be no association in life with Christ except through death and resurrection (John 12:24).
Wheat growing in Israel.