61 How can it be right to pass by Malachi, who at one time brings bitter charges against the priests, and reproaches them with despising the name of the Lord, and explains wherein they did this, by offering polluted bread upon the altar, and meat which is not firstfruits, which they would not have offered to one of their governors, or, if they had offered it, they would have been dishonoured; yet offering these in fulfilment of a vow to the King of the universe, to wit, the lame and the sick, and the deformed, which are utterly profane and loathsome. Again he reminds them of the covenant of God, a covenant of life and peace, with the sons of Levi, and that they should serve Him in fear, and stand in awe of the manifestation of His Name.
The law of truth, he says, was in his mouth, and unrighteousness was not found in his lips; he walked with me uprightly in peace, and turned away many from iniquity: for the priest's lips shall keep knowledge, and they shall seek the law at his mouth. And how honourable and at the same time how fearful is the cause! For he is the messenger of the Lord Almighty. Although I pass over the following imprecations, as strongly worded, yet I am afraid of their truth. This however may be cited without offense, to our profit. Is it right, he says, to regard your sacrifice, and receive it with good will at your hands, as if he were most highly incensed, and rejecting their ministrations owing to their wickedness.
Source: Orations (New Advent)