After the Words of Institution and before the distribution, the congregation sings the Agnus Dei, which is Latin for the first words of the canticle, “Lamb of God”. Three times we address the Lamb of God. Twice we ask for mercy. The third time we ask for peace.
We address the Lamb of God here because of what has just happened in the service. In the Lord’s Supper, we recognize Jesus not as shepherd, but as sacrificial lamb, after the sacrificial system of the Old Testament. A lamb was one of the appointed sacrifices for sins. Even before the appointment of the Levitical priesthood, Abraham was prepared to make a sacrifice at God’s request. Though God asked him to sacrifice his son, Isaac, God provided a lamb at the last minute for Abraham to sacrifice instead (Genesis 22). This served to point to what God Himself would do. He would willingly sacrifice His only begotten Son for the sins of the world.
When Jesus appeared before John at the Jordan River, John recognized Jesus for who He was (John 1:29): “Behold, the Lamb of God, who takes away the sin of the world.” This also brings to mind the utterances of the prophet Isaiah, especially in chapter 53, “… like a lamb that is led to the slaughter, and like a sheep that before its shearers is silent, so he opened not his mouth.” Indeed, in our service, we are at this point just preparing to encounter the Lamb of God as He comes to us in His sacrificed body and blood. Through His crucifixion and death, the Shepherd who cares for His sheep becomes the Sheep who is slain on their behalf.
In this prayer to Christ Himself, we remember the promises made in Scripture of what He does for us. We were “ransomed from the futile ways inherited from your forefathers, not with perishable things such as silver or gold, but with the precious blood of Christ, like that of a lamb without blemish or spot” (1 Peter 1:18-19). As we read in Ephesians 2, “He is our peace” because He reconciled us to the Father through the cross. It is appropriate that we here ask for Him to have mercy and to give us peace. Mercy only comes to us through the sacrifice for sins. Peace only comes with the comfort that our sins are forgiven, not held against us.
As we prepare to go the Lord’s Table where He distributes His gifts, we remember what it is all about. This is not just a symbolic meal of bread and wine. As we sing the Agnus Dei, we know that we will soon receive His true body and blood for the forgiveness of our sins. We pray for mercy and peace, trusting that He will be true to His promises. It is not with a false or tenuous hope that we sing, but with a sure confidence that what we ask for, we will indeed receive.