In its description of the mitzva of sefirat ha-omer in Parashat Emor, the Torah stresses the role of the korban omer, describing the sefira as beginning 'on the day in which the omer ha-tenufa was brought."
Sefira. Shaving. Our earliest sources make no mention of a ban on haircuts during Sefirat ha-Omer (the days between Pesach and Shavuot). The Ritz Giat, for example, refers only to marria