The Threshing Floor

The symbolism of the threshing floor deserves a mention. This is a place where wheat is separated from the chaff. The motif of fertile harvest, seed and bounty certainly adds to the significance that surrounds and envelops these verses. Redemption also is preceded by separation of good and evil. In our world, good and evil are inextricably intermixed. We might say that our reality is neither night nor day but a twilight, a time when light and darkness function together, when shadows appear solid and the real unreal. It is the task of man to separate light and darkness, to extract the good and join it to its ‘root’, so it can be redeemed. Then the evil will of itself perish and the good will be transformed into Godliness, as wheat becomes bread, as Boaz and Ruth become progenitors of the Messianic line. In Kabbalah this is known as Birur, or clarification, the first condition of Redemption.

Source: http://www.torah.org/learning/ruth/class27.html