The Feast of Weeks followed the Feast of Firstfruits by seven Sabbaths, plus one day, and during the Feast of Weeks, the Lord said He wanted this from Israel,
“And you shall offer with the bread seven lambs of the first year, without blemish, one young bull, and two rams. They shall be as a burnt offering to the LORD, with their grain offering and their drink offerings, an offering made by fire for a sweet aroma to the LORD” (Leviticus 23.18).
Seven lambs. The lamb represented innocence and perfection, and offering seven just escalated that imagery.
Later, the Bible reveals that Jesus is the Lamb of God, and as the Lamb of God, Jesus has seven horns and seven eyes (Revelation 5.6).