THE OMER WAS TOSSED IN THE WIND

Midrash Rabbah - Leviticus 28:2

R. Abin said: Come and observe how much anxiety Israel experienced on account of the commandment of the sheaf! …

The Sages, however, say: They used to thresh it … Then they spread it out in the Temple courtyard and the wind blew upon it, and then they brought it to the grist-grinders’ mill.