Exodus 23:16

The feast of harvest, i.e. of wheat harvest, for barley harvest was before this time. This feast was otherwise called pentecost. Quest. How were these the first-fruits, when a sheaf was offered to God in the feast of the passover? Answ. That sheaf was generally of barley, which was less considerable than their wheat; but this was the first-fruits of their wheat, which was their principal grain, and they had no bread before this time from the growth of that year. The feast of ingathering, to wit, of all the rest of the fruits of the earth, as of the vines and olives. This was also called the feast of booths, and of tabernacles. See Leviticus 13:43 Numbers 29:12 Deuteronomy 16:13. All their three feasts had a respect to the harvest, which began in the passover, was carried on at pentecost, and was fully completed and ended in this feast. In the end of the year; of the common or civil year, which began in September, as the sacred year began in March.