A sacrifice to God is an afflicted spirit; a crushed and humbled heart, O God, you do not spurn (Ps 50[51], 19). You have what you may offer him. Dont look around at your flock; dont prepare your ships; dont sail to the farthest provinces to bring back spices. Look in your heart for what is pleasing to God. Your heart has to be crushed. Why fear that it will die if crushed? There you have it: Create a clean heart in me, O God (Ps 50[51]: 12). Let the unclean heart be crushed, then, so that a clean heart may be created. (Augustine, Sermon 19, 3; PL 38, 134)