The firstfruits sheaf wasn’t the whole harvest, but it was a promise of the harvest to come.
Some of these festivals must await Israel’s entrance into 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. He shall wave the sheaf before the Lord, to be accepted on your behalf; on the day after the Sabbath the priest shall wave it” (Lev 23:10-11). So if the Passover pointed to the death of Christ, what could this festival called Firstfruits picture? H.K. Downie, in his book, Harvest Festivals, writes: “Our Lord, the true Paschal Lamb, was slain on the fourteenth day of the month, dying, as we are told, about the ninth hour (Lk 23:44-46). A little later on,…the friends of Jesus took Him down from the cross, laid Him in Joseph’s new tomb, and then went home to prepare for the coming Sabbath. About the same time, the delegates of the Sanhedrin crossed the Brook Kidron and cut down a sheaf of wheat from among the standing grain, and, taking it to the temple, left it there to be waved before the Lord ‘on the morrow after the Sabbath.’ There the Lord lay in His tomb and there the sheaf lay in the temple. The morning after the Sabbath, the first day of the week arrived and what happened? The high priest waved the wave sheaf in empty form, ignorant of the fact that earlier that day the true Sheaf had been waved before the Lord.” 1 Corinthians 15:20 says, “Christ is risen from the dead, and has become the firstfruits of those who have fallen asleep.” So we, part of the coming harvest, declare with joy: “Blessed be the God and Father of our Lord Jesus Christ, who according to His abundant mercy has begotten us again to a living hope through the resurrection of Jesus Christ from the dead” (1 Pet 1:3). Amen to that!