Therefore by Him let us continually offer the sacrifice of praise to God, that is, the fruit of our lips, giving thanks to His name.
What happens in the rite
The priest and deacons prepare the altar and vessels, the canonical hours are prayed, and the priest washes his hands before the holy service. The priest then examines the holy bread, chooses the Lamb, blesses the gifts, and processes with the selected offering. The bread and wine are placed on the altar and covered according to the rite.
This is the beginning of the visible movement toward Holy Communion. The gifts are still bread and wine at this point, but they have been set apart for the Eucharistic service. The whole Church is being taught to offer what God has given and to wait for Him to sanctify it.
Why the Lamb is offered
The Offering of the Lamb teaches that worship is offering, thanksgiving, and surrender to God. Bread and wine are brought from creation and placed before the Creator. The chosen Lamb points to Christ, the Lamb of God, who offers Himself for the life of the world and gives Himself back to the faithful as holy Communion.
The Church therefore begins the Liturgy by giving, not by taking. She brings the gifts, prayer, repentance, and thanksgiving before God. God receives the offering and gives the faithful a gift beyond anything human beings could produce: communion in the holy Body and precious Blood of Christ.