United States Conference of Catholic Bishops
The Lord's Teaching Through the Twelve Apostles to the Nations.
(Late first or early second century A.D.)
Chapter 9. The Thanksgiving (Eucharist)
Now concerning the Thanksgiving (Eucharist), thus give thanks. First, concerning the cup: We thank you, our Father, for the holy vine of David Your servant, which You made known to us through Jesus Your Servant; to You be the glory forever. And concerning the broken bread: We thank You, our Father, for the life and knowledge which You made known to us through Jesus Your Servant; to You be the glory forever. Even as this broken bread was scattered over the hills, and was gathered together and became one, so let Your Church be gathered together from the ends of the earth into Your kingdom; for Yours is the glory and the power through Jesus Christ forever. But let no one eat or drink of your Thanksgiving (Eucharist), but they who have been baptized into the name of the Lord; for concerning this also the Lord has said, Give not that which is holy to the dogs. Matthew 7:6
Chapter 10. Prayer After Communion
But after you are filled, thus give thanks: We thank You, holy Father, for Your holy name which You caused to tabernacle in our hearts, and for the knowledge and faith and immortality, which You made known to us through Jesus Your Servant; to You be the glory forever. You, Master almighty, created all things for Your name's sake; You gave food and drink to men for enjoyment, that they might give thanks to You; but to us You freely gave spiritual food and drink and life eternal through Your Servant. Before all things we thank You that You are mighty; to You be the glory forever. Remember, Lord, Your Church, to deliver it from all evil and to make it perfect in Your love, and gather it from the four winds, sanctified for Your kingdom which You have prepared for it; for Yours is the power and the glory forever. Let grace come, and let this world pass away. Hosanna to the God (Son) of David! If anyone is holy, let him come; if anyone is not so, let him repent. Maranatha. Amen. But permit the prophets to make Thanksgiving as much as they desire.
Source. Translated by M.B. Riddle. From Ante-Nicene Fathers, Vol. 7. Edited by Alexander Roberts, James Donaldson, and A. Cleveland Coxe. (Buffalo, NY: Christian Literature Publishing Co., 1886.) Revised and edited for New Advent by Kevin Knight. <http://www.newadvent.org/fathers/0714.htm>.