The first prayer is from Saint Ambrose (340-397)
O loving Lord Jesus Christ, I a sinner, presuming not on my own merits, but trusting in Thy mercy and goodness, with fear and trembling approach the table of Thy most sacred banquet.
For I have defiled both my heart and body with many sins, and have not kept a strict guard over my mind and my tongue. Wherefore, O gracious God, O awful Majesty, I a wretched creature, entangled in difficulties, have recourse to Thee the fount of mercy;
To Thee do I fly that I may be healed, and take refuge under Thy protection, and I ardently desire to have Him as my Savior, Whom I am unable to withstand as my Judge.
To Thee, O Lord, I show my wounds, to Thee I lay bare my shame. I know that my sins are many and great, on account of which I am filled with fear.
But I trust in Thy mercy, of which there is no end. Look down upon me, therefore, with the eyes of Thy mercy, O Lord Jesus Christ, eternal King, God and man, crucified for men.
Hearken unto me, for my hope is in Thee; have mercy on me who am full of misery and sin, Thou Who wilt never cease to let flow the fountain of mercy.
Hail, Victim of salvation, offered for me and for all mankind on the tree of the cross. Hail, noble and precious Blood, flowing from the wounds of my crucified Lord Jesus Christ and washing away the sins of the whole world.
Remember, O Lord, Thy creature, whom Thou hast redeemed with Thy Blood. I am grieved because I have sinned, I desire to make amends for what I have done.
Take away from me, therefore, O most merciful Father, all my iniquities and sins. That I may be purified both in soul and body, let me partake of the holy of holies;
And grant that this holy gift of Thy Body and Blood, of which though unworthy I propose to receive, may be to me the remission of my sins, the perfect cleansing of my offenses, the means of driving away all evil thoughts and of renewing all holy desires, the accomplishment of works pleasing to Thee, as well as the strongest defense for soul and body against the snares of my enemies. Amen.
The Second prayer is from Saint Thomas Aquinas (1225-1274)
Almighty and eternal God, behold, I approach the Sacrament of Thine only begotten Son, our Lord Jesus Christ.
I approach as one who is sick to the physician of life, as one unclean to the fountain of mercy,
as one blind to the light of eternal brightness, as one poor and needy to the Lord of heaven and earth.
Therefore I beseech Thee, of Thine infinite goodness, to heal my sickness, to wash away my filth, to enlighten my blindness, to enrich my poverty, and to clothe my nakedness,
That I may receive the Bread of angels, the King of kings, and the Lord of lords;
with such reverence and humility, with such contrition and devotion, with such purity and faith, with such purpose and intention, as may benefit the salvation of my soul.
Grant, I beseech Thee, that I may receive not only the Sacrament of the Body and Blood of our Lord, but also the fruit and virtue of this Sacrament.
O most indulgent God, grant me so to receive the Body of Thine only begotten Son, our Lord Jesus Christ, which He took of the Virgin Mary, that I may be found worthy to be incorporated with His mystical Body and numbered among His members.
O most loving Father, grant that I may one day contemplate forever, face to face, Thy beloved Son, Whom now on my pilgrimage I am about to receive under the Sacramental veils;
Who liveth and reigneth with Thee in the unity of the Holy Ghost, God, world without end. Amen.