Pentecost is the only annual Holy Day commanded by God that does not come on a specific date. Rather, it is counted year by year, always falling on day 50 of a count that begins with the wave sheaf offering on Sunday.
Normally this is a simple calculation, but questions inevitably arise during years when the Days of Unleavened Bread begin on a Sunday and end on a weekly Sabbath. Would the wave sheaf have been offered on the first Holy Day, or on the Sunday after the last Holy Day (thus falling outside the Days of Unleavened Bread)? The year 2005 is such a year, and it is important that we understand the Bible answer to this question.
First, we should review God's instructions in Leviticus 23:4–21. After reminding Israel about the Passover and Days of Unleavened Bread, God added instructions that would only apply after the nation had crossed the Jordan River and entered the Promised Land: "When you come into the land which I give to you, and reap its harvest, then you shall bring a sheaf of the firstfruits of your harvest to the priest" (v. 10). The priest was to "wave the sheaf before the Lord" on the "day after the Sabbath" (v. 11). This began the 50-day count to Pentecost (vv. 15–16). Only after this ceremony could the people begin eating the new harvest (v. 14).
Keeping these instructions in mind, we can look ahead almost 40 years to the very first Passover season after Israel entered the Promised Land. Israel crossed the Jordan River and entered the land on the tenth day of the first month (Joshua 4:19). Immediately afterward, those who had been born during the wandering in the wilderness were circumcised (5:2–9).
The Israelites encamped in Gilgal, and "kept the Passover on the fourteenth day of the month at twilight on the plains of Jericho" (v. 10). We then read that "they ate of the produce of the land on the day after the Passover, unleavened bread and parched grain on the very same day" (v. 11). The manna ceased, and Israel "ate the food of the land of Canaan that year" (v. 12). Considered in the context of Leviticus 23:10 and 23:14, this can only mean that the wave sheaf was offered on the day after the Passover: the first Holy Day of Unleavened Bread. In other words, the first day of Unleavened Bread came on a Sunday, that year—and that was when the wave sheaf was offered, not on the Sunday that came a week later, after the two Holy Days of Unleavened Bread. Remember, food preparation was specifically permitted on the two Holy Days of Unleavened Bread (Exodus 12:16).
Think about it! If Israel had begun to eat parched ears and bread from the harvest of Canaan before the wave sheaf offering, this would mean that the first thing they had done upon entering the land was ignore Moses' clear instructions in Leviticus 23:10. We know that this did not happen, because we are specifically told that Joshua "left nothing undone of all that the Lord had commanded Moses" (Joshua 11:15).
Some become confused when they see that the King James Version and Strong's Concordance both wrongly refer to Israel eating the "old corn" rather than the fresh harvest in Joshua 5:11–12. No other major translations or reference works make this mistake, and any Hebrew lexicon will demonstrate that the Hebrew word used here in Joshua does not refer to consuming the previous year's harvest. Remember that any old grain from the previous spring would have been stored within the city walls of Jericho in preparation for the siege. Only the grain in the field would have been accessible to Israel. Furthermore, we are told that Israel ate parched grain on the first Holy Day—a reference to the means of preparing still-green ears of barley, not grain that was a year old.
We are not left to speculation or human reasoning to determine when to begin the Pentecost count. Rather, God has preserved an example in Scripture to make the point clear. When we observe Pentecost on June 12 this year, we can know that we are following the example God has given in Scripture.