Aviv

Aviv (or Abib) is barley at the stage of ripening — “in the ear,” nearly ready to harvest. It is the condition the Wave Sheaf depended on: the grain had to be aviv before it could be cut and waved, which is why the timing of the Feast of Weeks bent to the harvest rather than to a fixed date. Synonyms: Abib, barley in the ear, ripening barley.

See The Sliding Nature of The Feast of Weeks