I. Here are four necessary duties that we are called to, all amounting to the same:—1. We must repent; we must change our mind and change our ways; we must be sorry for what we have done amiss and ashamed of it, and go as far as we can towards the undoing of it again. 2. We must turn ourselves from all our transgressions, v. 30 and again v. 32. Turn yourselves, face about; turn from sin, nay, turn against it as the enemy you loathe, turn to God as the friend you love. 3. We must cast away from us all our transgressions; we must abandon and forsake them with a resolution never to return to them again, give sin a bill of divorce, break all the leagues we have made with it, throw it overboard, as the mariners did Jonah (for it has raised the storm), cast it out of the soul, and crucify it as a malefactor. 4. We must make us a new heart and a new spirit. This was the matter of a promise, ch. xi. 19. Here it is the matter of a precept. We must do our endeavour, and then God will not be wanting to us to give us his grace. St. Austin well explains this precept. Deus non jubet impossibilia, sed jubendo monet et facere quod possis et petere quod non possis—God does not enjoin impossibilities, but by his commands admonishes us to do what is in our power and to pray for what is not.