Overview:

On the second night of Pesach, or the first night of the Feast of Unleavened bread, we begin counting the Omer for 49 days (or 7 weeks). Shavuot is the culmination of the counting on the 50th day after Pesach. This Holy Day celebrates the earthly ingathering of firstfruits from the harvest of our fields, specifically when we have entered and settled into the Holy Land of Israel.

On the very first Shavuot after leaving Egypt, however, our Israelite ancestors had not yet entered into the promised land. Thus, the first Shavuot was truly the celebration of Hashem's first-fruit of His harvest. The seeds which Hashem had planted when He brought us out of Egypt had 49 days to be planted in the dirt of the desert, be watered by the miraculous waters from the split rocks and abundant springs, and be fed by the manna of Heaven. Then, on the 50th day, Hashem's harvest was ready to be harvested.

On the 3rd New Moon after leaving Egypt, Hashem called to Moshe and commanded that the people get ready and stay pure for the third day. On the third day, Hashem moved from among the people and decended on the top of Mt. Sinai. From the top of the Mountain, Hashem began to proclaim the commandments of the Torah. This giving of the Jewish law was the first real step in the first fruit peole of Hashem (the Jewish people) becoming the first fruit nation of Hashem: The Nation of Israel. (Jeremiah 2:3).

The first true celebration of Shavuot as the Festival of Weeks, or Festival of the First Fruit Ingathering of the wheat harvest began when Joshua finally led our Jewish Ancestors into the Promised Land.