Q. Why do we count the Omer?
A. The commandment to count the days and weeks between Pesach and Shavu’ot derives from Leviticus 23:15, which says, “You shall count… from the morrow of the Sabbath” (meaning the day after the first day of Pesach). Another verse (Deuteronomy 16:9) says this count begins “when the scythe is first put to the standing grain”.
The latter statement is taken to mean that the count begins from the date of the beginning of the barley harvest. In this sense it may connect the two harvests, the barley and the wheat.
Some commentators claim that the count is made so that the Jews in Israel who traditionally came to Jerusalem for Pesach and then returned home to continue the harvesting would make sure to return to Jerusalem in time for the next holiday (Shavu’ot), seven weeks away.
Others claim that the count was made to indicate the relationship between the themes of the two festivals. Pesach celebrates the freedom achieved by the Exodus from Egypt, while Shavu’ot marks the revelation of the Torah at Mount Sinai. Revelation cannot be achieved without freedom, and freedom is fruitless without a goal and purpose.