O almighty and everlasting Lord God,
Jesus Christ our Lord,
be merciful to me,
and forgive my sins,
through the partaking of your most blessed body and blood;
for you have spoken, saying:
“Whoever feeds on my flesh and drinks my blood,
abides in me, and I in him.”
Therefore create in me a clean heart,
and renew a right spirit within me;
and uphold me with your free Spirit,
and deliver me from all the snares
and malice of the devil;
that I may share in the joys of heaven.
Source: Sarum Rite
Source of this version: http://www.catholicliturgy.com/index.cfm/FuseAction/Prayer/Index/100/PrayerIndex/30
O almighty and everlasting Lord God, Jesus Christ our Lord, be merciful unto my sins, through the partaking of Thy most blessed Body and Blood; for Thou hast spoken, saying: He that eateth My Flesh and drinketh My Blood, abideth in Me, and I in him.
Wherefore I humbly beseech Thee to create in me a clean heart, and renew a rightful spirit within me; and deign to establish me with Thy free Spirit, and to deliver me from all the snares and malice of the devil; that I may be found worthy to have a share in the joys of heaven. Amen.
“Whoever eats my flesh” is a reference to John 6:54 and refers to taking in everything Jesus is and says, not only his body and blood in the Lord’s Supper. Jesus spoke the words some time before the Supper was instituted.
“Create in me a clean heart…” is a reference to Psalm 51:10-12