wheat
Peter was the wheat, his self-confidence the chaff.
Compare (Matthew 13:30); (John 5:24); (John 10:23); (Romans 6:1); (Romans 6:2); (1 John 1:8); (1 John 2:1).
Related Commentaries of Luke 22:31
Luke 22:31
31 And the Lord said, Simon, Simon, behold, Satan hath desired to have you, that he may sift you as wheat: