Leviticus 23:9-21 outlines God's instructions for the wave sheaf offering, the seven-week count, the Feast of Weeks, or Pentecost. And when we understand the purpose of God's holy days and how they outline God's plan of salvation, we see that this entire period focuses on what the first of the firstfruits has made possible by preparing the saints for God's spiritual harvest. Now the full impact of the wave sheaf offering on God's people becomes clear when we recognize the importance of the counting required for observing Pentecost.
So the wave sheaf consisted of an omer of barley still on the stalk and cut at the start of the spring harvest. Now because it came from the very beginning of the firstfruits, it is called the first of the firstfruits. So each Israelite with a harvest was required to offer an offering. Then a priest would lift and wave each sheaf before God for acceptance. Now in the Old Testament, the wave sheaf offering represented a thankful acknowledgment to God as the Giver of the harvest. In this way, it was sanctified or dedicated to Him.
Now in the New Testament, the spiritual purpose of this offering is revealed. The Old Testament places God's festivals within the agricultural harvest. But in the New Testament, these agricultural harvests become types of God's spiritual harvest of people into His Kingdom. So this period begins with the offering of the barley sheaf symbolizing Christ and then ends 50 days later with two leavened loaves representing God's people, imperfect yet accepted into His Kingdom. Together, these elements illustrate the full scope of God's work with His firstfruits, from Christ's perfect sacrifice to inclusion of His followers in His Family.