Related על ראש השנה 31:15

Similarly, you find it with the Omer of the Man: When the month comes in due time, it immediately ceases; but if not, then it stays for three days. R. Akiba said: The Torah said, Bring barley on the Passover, for it is the time of barley that because of you the grain will be blessed. Plant wheat as firstfruits Feast of Pentecost, for it is the season of wheat, that because of thee the fruit of the tree shall be blessed [Bring] the bounty of water at the Feast of Tabernacles, for it is the season of rain, that because of thyself the rain shall be blessed. Speak before him the Scriptures of kingship, that ye make him king over all his works; the Scriptures of his remembrance, that your remembrance shall be before him for good; the Scriptures dealing with the blowing of horns, that your prayer come before him through the voice of the horns.