If Shavuot commemorates the wheat harvest why do you read the story of Ruth and the barley harvest?

Answer 1

Shavuot commemorates the giving of the Torah on Mt Sinai and its acceptance by the Jewish people.

The story of Ruth is read because Ruth was a convert to Judaism and accepted the Torah voluntarily.

Shavuot is also referred to as the festival of harvesting - as it falls in the beginning of the summer.

Background info:

Shavuot has several different names in The Bible. In Exodus 34:22 and Deuteronomy 16:10 it is referred to as Chag Shavuot, "Feast of Weeks," one of the harvest festivals on which pilgrims brought offerings to the Temple in Jerusalem. In Numbers 28:26 it is called Yom ha-Bikkurim or "Day of the First Fruits"; Shavuot was a celebration of the harvest of the first fruits of late spring; and dates, figs, grapes, pomegranates, and olives, in addition to wheat and barley, were brought to the Temple by worshipers. In Exodus 23:16 Shavuot is called Chag ha-Katzir, meaning the "Harvest Feast"; Shavuot occurred at the conclusion to the barley harvest, which had begun at Passover, and began the early spring wheat harvest, since in Israel the month of Sivan signals the end of spring and the beginning of summer. The wheat-harvest aspect of Shavuot was observed by bringing to the Temple an offering of two bread loaves baked from the new grain harvest. The pilgrims who came to Jerusalem would gather and celebrate the festival joyously. The commandment to celebrate this holiday is found in Leviticus 23:15-21.