O Lord Jesus Christ,
the great High Priest,
who dost call chosen souls to offer Thee in sacrifice
and to assist Thee in saving souls,
I beseech Thee to grant me this high grace
though I am most unworthy of it;
make me carefully to prepare my heart to receive it
and to keep myself pure and lowly
that Thou mayest call me to serve Thee at Thine altar.

Amen.

O Mary, Mother of God and my dear mother too,
obtain for me this grace from the Sacred Heart of thy dear
Son.

(Taken from Catholic Online)