Ruth 3:2

He winnoweth barley. In Palestine the winnowing of grain was accomplished, as it is today, by tossing it high into the air with a shovel or a fork, or from a shallow vessel or a sieve, so that the grain would of its own weight fall in one place and the chaff be carried away by the wind. Winnowing was usually done in the cool of the evening.

The threshingfloor. In a Palestinian harvest the process of separating the grain from the straw was generally carried on at a threshing floor under the open sky (see Judges 6:37). This was usually a large, hard, flat, circular area of ground 40 or 50 ft. in diameter. Either the whole sheaves or the ears cut from the sheaves were spread upon the earthen floor, and oxen were driven about the floor to trample out the kernels. Sometimes a sled weighted with stones was pulled by the oxen as they circled the floor. After winnowing, the grain was finally passed through a sieve to free it from grit and dirt. Then it was stored, ready for grinding.