Boyd’s Bible Dictionary:
Was separated from the grain by throwing all into the air from sheets, or forks, the wind carrying away the chaff (Psa. 1:4; Isa. 17:13; Hos. 13:3; Zeph. 2:2).
Concise Bible Dictionary:
The refuse of threshed and winnowed grain—the husk of the wheat. Used symbolically for that which is quickly consumed, or easily swept away by the wind—worthless people (Psa. 1:4; Psa. 35:5; Isa. 5:24; Jer. 23:28). The wicked also are compared to chaff to be burned up with unquenchable fire—eternal punishment (Matt. 3:12; Luke 3:17).
Psyllium husk
Rice
Strong’s Dictionary of Hebrew Words:
Meaning:
or mowts (Zephaniah 2:2) {motes}; from 4160; chaff (as pressed out, i.e. winnowed or (rather) threshed loose)