Smith's Bible Dictionary

Chaff the husk of corn or wheat which was separated from the grain by being thrown into the air, the wind blowing away the chaff, while the grain was saved. The carrying away of chaff by the wind is an ordinary scriptural image of the destruction of the wicked and of their powerlessness to resist God’s judgments. (Psalm 1:4; Isaiah 17:13; Hosea 13:3; Zephaniah 2:2)