Used, in Amos 9:9, of a small stone or kernel; in Matt. 13:31, of an individual seed of mustard; in John 12:24, 1 Cor. 15:37, of wheat. The Hebrews sowed only wheat, barley, and spelt; rye and oats are not mentioned in Scripture.
Easton’s Bible Dictionary
Grain
Easton’s Bible Dictionary (1897), public domain. Text via Theographic Bible Metadata, CC BY-SA 4.0.