Proverbs 15:8,9 - Joseph Benson’s Commentary on the Old and New Testaments

The sacrifice of the wicked Or the religious services, yea, the best and most costly of them, one kind being put for all the rest; is an abomination to the Lord Because not offered with a sincere desire to glorify him, nor from a principle of faith and love, but is made a cloak for sin, is used to silence the clamours of conscience, and commute for the neglect of obedience to God's moral commands: see the margin. It is justly observed by Mr. Scott here, that “the most costly sacrifices of the wicked, under the Mosaic law, must have been an abomination to the Lord; because their whole way was abominable to him, and because of their corrupt motives; and the case is precisely the same with all external acts of worship, nay, with the largest oblations, and most liberal alms of the impenitent and unbelieving, under the Christian dispensation. For, by them, they either mean nothing determinate, or they intend to cover their sins, to bribe their Judge, to make compensation for past, or to purchase indulgences for future transgressions: they put their services in the stead either of Christ's atonement, or of holy obedience; they present them with hypocritical hearts; and they grossly affront the holy God by supposing that he can be imposed on by forms or gifts, or pleased by them while they are enemies to his justice, his authority, and his grace.” But the prayer of the upright is his delight Their cheapest and meanest services, even their very prayers, are acceptable, yea, highly pleasing to him, and prevail for great blessings from him.