From the Haydock BibleVer. 12.
Of all the petitions this alone is repeated twice. God puts our judgment in our own hands, that none might complain, being the author of his own sentence. He could have forgiven us our sins without this condition, but he consulted our good, in affording us opportunities of practising daily the virtues of piety and mildness. (St. Chrysostom, hom. xx.) --- These debts signify not only mortal
sins, as St. Augustine often teaches. Therefore every man, be he ever so just, yet because he cannot live without venial sin, ought to say this prayer. (Cont. 2 epis. Pelag. lib. i. chap. 14.) --- (lib. xxi. de civit. Dei. chap. xxvii.) (Bristow)