§1365
Sacraments › … › V. The Sacramental Sacrifice Thanksgiving, Memorial, Presence
The sacrificial memorial of Christ and of his Body, the Church
Because it is the memorial of Christ's Passover, the Eucharist is also a sacrifice. The sacrificial character of the Eucharist is manifested in the very words of institution: "This is my body which is given for you" and "This cup which is poured out for you is the New Covenant in my blood." In the Eucharist Christ gives us the very body which he gave up for us on the cross, the very blood which he "poured out for many for the forgiveness of sins."
Source: Catechism of the Catholic Church (Vatican.va)