St Gregory Nazianzen is writing to Amphilochius, Bishop of Iconium.
SCARCELY yet delivered from the pains of my illness, I hasten to you, the guardian of my cure. For the tongue of a priest meditating of the Lord raises the sick.
Do then the greater thing in your priestly ministration, and loose the great mass of my sins when you lay hold of the Sacrifice of Resurrection. […]
But, most reverend friend, cease not both to pray and to plead for me when you draw down the Word by your word, when with a bloodless cutting you sever the Body and Blood of the Lord, using your voice for the glaive.
Letter CLXXI. “Glaive” is an archaic word for a sword, symbolising the lance used upon Jesus on the cross, and the small knife used to cut the bread at Holy Communion.
WE give thanks to thee, invisible king, who in thy measureless might hast created all things and in the abundance of thy mercy brought all things from nothing into being.
Do thou, O Master, look from heaven upon them that have bowed their heads. For they bow not to flesh and blood, but to thee, thou dread God. Therefore do thou, O Master, smooth the way that lies before us for good, according to the need of each. Sail with them that sail; journey with them that journey; heal the sick, O physician of our souls and bodies.
By thy only-begotten Son’s grace and compassion and love for mankind, with whom thou art blessed, with thy all-holy and good and life-giving Spirit, now and for ever and to the ages of the ages. Amen.
Give ear, Lord Jesus Christ our God, from thy holy habitation, and from the throne of glory in the Kingdom, and come to sanctify us, who sitteth with the Father above, and who art with us invisibly here. And deign with thy powerful hand to give unto us from thy immaculate body and thy precious blood, and through us, to all the people.
God me merciful to me a sinner, and have mercy upon me (three times).
Liturgy of St John Chrysostom (at Analogion). This is prayed by the priest in a low voice, immediately before the Communion.