Counting The Omer – Preparation for Rosh Hashana

The Mishna teaches that Shavuot is a Rosh Hashana. Therefore, just as we use the time period before Rosh Hashana, the month of Elul, to prepare for Rosh Hashana, we must use the

time period before Shavuot, the Sefirah, to do Teshuva and prepare for the Rosh Hashana of Shavuot. (Ma’or Vashemesh – Bichukotai)