13 “Lord, Your mercy is for everlasting.”...Not for a time only do I desire to be freed. “Your mercy is for everlasting,” wherewith You have freed the martyrs, and so hast quickly taken them from this life. “Despise not Thou the works of Your own hands.” I say not, Lord, “despise not the works of my hands:” of my own works I boast not. “I sought,” indeed, “the Lord with my hands in the night season before Him, and have not been deceived;” but yet I praise not the works of my own hands; I fear lest, when You shall look into them, Thou find more sins in them than deserts. Behold in me Your Work, not mine: for mine if You see, You condemn; Yours, if You see, You crown. For whatever good works there be of mine, from You are they to me; and so they are more Yours than mine. Therefore whether in regard that we are men, or in regard that we have been changed and justified from our iniquity, Lord, “despise not Thou the works of Your own hands.”
Source: The Enarrations, or Expositions, on the Psalms (New Advent)