My LORD’s BibleApostolic Constitutions, Book VII 45
1But let him pray thus after the foregoing prayer, and say: O God Almighty, the Father of Your Christ, Your only begotten Son, give me a body undefiled, a heart pure, a mind watchful, an unerring knowledge, the influence of the Holy Ghost for the obtaining and assured enjoying of the truth, through Your Christ, by whom glory be to You, in the Holy Spirit, forever. Amen. We have thought it reasonable to make these constitutions concerning the catechumens.