As a close relative, Boaz might serve as a redeemer for Ruth and Naomi (see study notes on Ruth 2:20; 3:9).
The threshing floor was a flat surface made of stone or hardened earth. The farmer spread sheaves of grain over it and beat them to separate the grain from the straw. Then the farmer would winnow by tossing the mixed straw and grain into the air with a wooden fork or shovel. The breeze carried the lighter straw and chaff away, while the heavier grains fell back to the threshing floor.