15 What He requires of man, let us see; what tribute our God, our Emperor and our King does enjoin us; since He has willed to be our King, and has willed us to be His province? Let us hear His injunctions. Let not a poor man tremble beneath the injunction of God: what God enjoins to be given to Himself, He does Himself first give that enjoins: be ye only devoted. God does not exact what He has not given, and to all men has given what He does exact. For what does He exact?
Let us hear now: “I will not reprove you because of your sacrifices”. I will not say to you, Wherefore have you not slain for me a fat bull? Why have you not selected the best he-goat from your flock? Wherefore does that ram amble among your sheep, and is not laid upon mine altar? I will not say, Examine your fields and your pen and your walls, seeking what you may give Me. “I will not reprove you because of your sacrifices.” What then: Do You not accept my sacrifices? “But your holocausts are always in My sight”.
Certain holocausts concerning which it is said in another Psalm, “If You had desired sacrifice, I would surely have given, with holocausts You will not be delighted:” and again he turns himself, “Sacrifice to God is a troubled spirit, a heart broken and humbled God does not despise.” Which be then holocausts that He despises not? Which holocausts that are always in His sight? “Kindly, O Lord,” he says, “deal in Your good will with Sion, and be the walls of Jerusalem built, then shall You accept the sacrifice of righteousness, oblations, and holocausts.”
He says that certain holocausts God will accept. But what is a holocaust? A whole consumed with fire: causis is burning, holon is whole: but a “holocaust” is a whole consumed with fire. There is a certain fire of most burning love: be the mind inflamed with love, let the same love hurry off the limbs to its use, let it not allow them to serve cupidity, in order that we may wholly glow with fire of divine love that will offer to God a holocaust. Such “holocausts of yours are in My sight always.”
Source: The Enarrations, or Expositions, on the Psalms (New Advent)