'Threshing floor' in the Bible

His winnowing shovel [Note: This was a process whereby grain was tossed into the air so that the wind could blow the husks away, leaving only good grain on the ground] is in His hand and He will completely clear off His threshing floor [by removing all of the husks]. And He will gather His wheat into the barn, but will burn up the husks with a fire that will never go out."