Psalms 51:13 [Then] will I teach transgressors thy ways; and sinners shall be converted unto thee.
Ver. 13. Then will I teach transgressors thy ways] Instruunt nos Patres tum docentes, tum labentes, saith Augustine: Two ways the saints teach us. First, By their doctrine. Secondly, By their falls and failings. David had taught men this last way to his cost, that it is triste mortalitatis privilegium licere aliquando peccare; now he promiseth by his example and instruction to teach transgressors, those that are in the very bonds and hands of the devil, God's ways of mercy to the penitent; and that they must either turn to God or burn for ever in hell.
And sinners shall be converted unto thee] They shall give not the half, but the whole turn; and it shall appear by them. The turning of a sinner from evil to good is like the turning of a bell from one side to another; you cannot turn it but it will make a sound, and report its own motion.