Leviticus 23:6
And on the fifteenth day of the same month is the feast of unleavened bread unto the LORD: seven days ye must eat unleavened bread. And on the fifteenth day of the same month is the feast of unleavened bread unto the LORD: seven days ye must eat unleavened bread.
The fifteenth day of the same month begins a seven-day Feast of Unleavened Bread unto the Lord that follows the Passover, belonging to the yearly cycle of sacred gatherings to be observed annually. Its first day and its seventh day are days of holy convocation on which no servile work is to be performed. On the second day of the feast the first fruits of the year's harvest are presented before God, a sheaf of barley brought before the Lord.
Barley is the earliest grain in Palestine, and at the opening of the feast it is beginning to ripen. The priest waves a sheaf of this grain before the altar of God as an acknowledgment that all belongs to Him. The harvest is not to be gathered until this ceremony of waving has been performed.
All the ceremonies of the feast were types of the work of Christ. The unleavened bread itself represented the Saviour.