The act of winnowing is used several times in the Bible. Usually, the word is used figuratively to describe a sort of judgement. (Except in Ruth 3:2, where the literal act is referred to). Acccording to The New Manners and Customs of the Bible, winnowing is the process by which grain is seperated from the inedible parts. “The stalks are thrown into the air with a wooden shovel or a wooden fork having two or three prongs and a handle three or four feet long (also called a “fan”). The wind blows away the chaff and the straw, letting the heavier pure grain fall back to the ground. As a rule this was done in the evening or during the night, when the west wind from the sea was blowing, which was a moderate breeze and fittend for the purpose” (404).
Probably the most recognized verse is in Matthew (Also in Luke 3:17) where John the Baptist is addressing the Pharisees. “But after me will come one who is more powerful than I, whose sandals I am not fit to carry. He will baptize you with the Holy Spirit and with fire. His winnowing fork is in his hand, and he will clear his threshing floor, gathering his wheat into the barn and burning up the chaff with unquenchable fire” (Matt. 3:11-12). He describes Christ as a farmer who will come and harvest the grain, seperating the wheat from the chaff. It is clear that John is describing how Christ will gather some men unto himself (wheat) and seperate them from the wicked men (chaff), who will be consumed with unquenchable fire. John is speaking of the judgement of Christ.