Many thanks to Fr. Peter for recently exposing and explaining the ten “secret” prayers offered up by every priest at every Mass. In case you missed his series of sermons, here’s a catch-up, courtesy of parishableitems blog;

Did you know that the Church gives priests celebrating the Mass several prayers to say in a low voice, such that few (if any) in the church hear them? These are called the “secret” prayers (from the Latin word for “hidden.”)
May the great beauty of these prayers inform and inspire your own devotion at Holy Mass.
The priest, before proclaiming the Gospel, pauses in front of the altar to bow and pray:
“Cleanse my heart and my lips, almighty God, that I may worthily proclaim your holy Gospel.”
At the end of the Gospel, the priest (or proclaiming deacon) kisses the book and prays:
“Through the words of the Gospel may our sins be wiped away.”
During the Offertory, the priest (or assisting deacon) pours a little water into the chalice of (unconsecrated) wine and prays:
“By the mystery of this water and wine may we come to share in the divinity of Christ, who humbled himself to share in our humanity.”
After thanking God for the gifts of bread and wine He has given us to offer (“Blessed are you, Lord God of all creation…”) the priest bows behind the altar and prays:
“With humble spirit and contrite heart may we be accepted by you, O Lord, and may our sacrifice in your sight this day be pleasing to you, Lord God.”
While the priest washes his hands, he prays:
“Wash me, O Lord, from my iniquity and cleanse me from my sin.”
During the “Lamb of God,” the priest places a small piece of the Host into the chalice, praying:
“May this mingling of the Body and Blood of our Lord Jesus Christ bring eternal life to us who receive it.”
At the end of the “Lamb of God,” the priest joins his hands and prays one of these two prayers:
1. “Lord Jesus Christ, Son of the living God, who, by the will of the Father and the work of the Holy Spirit, through your death gave life to the world, free me by this, your most holy Body and Blood from all my sins and from every evil; keep me always faithful to your commandments, and never let me be parted from you.”
2. “May the receiving of your Body and Blood, Lord Jesus Christ, not bring me to judgment and condemnation, but through your loving mercy be for me protection in mind and body and a healing remedy.”
Before consuming the Body of Christ, the priest prays:
May the Body of Christ keep me safe for eternal life.
Before consuming the Blood of Christ from the chalice, the priest prays:
May the Blood of Christ keep me safe for eternal life.
Finally, while purifying the sacred vessels following the distribution of Communion, the priest prays:
“What has passed our lips as food, O Lord, may we possess in purity of heart, that what has been given to us in time may be our healing for eternity.”