הִנֵּה־הוּא זֹרֶה אֶת־גֹּרֶן הַשְּׂעֹרִים הַלָּיְלָה

A threshing floor is an area where one pounds the grain to separate the wheat from the chaff.

After threshing comes winnowing which is when the wheat is thrown into the air so that the chaff blows away and the wheat kernels remain.

A threshing floor - גרן