For I desired {f} mercy, and not sacrifice; and the knowledge of God more than burnt offerings.

(f) He shows to what his doctrine was aimed at, that they should unite the obedience of God, and the love of their neighbour, with outward sacrifices.

Wesley's Notes

6:6 For - I so hewed and slew them, because they did not what I most of all required; they were full of sacrifices, but either to idols, or else in formality and pride. Mercy - Compassion and charity towards men, this one principal duty of the second table put for all. In this I delight, I have found little of this among you. Not sacrifice - Rather than sacrifice. The knowledge of God - The affectionate knowledge of God, which fills the mind with reverence of his majesty, fear of his goodness, love of his holiness, trust in his promise, and submission to his will.

Jamieson-Fausset-Brown Bible Commentary

6. mercy-put for piety in general, of which mercy or charity is a branch.

not sacrifice-that is, "rather than sacrifice." So "not" is merely comparative (Ex 16:8; Joe 2:13; Joh 6:27; 1Ti 2:14). As God Himself instituted sacrifices, it cannot mean that He desired them not absolutely, but that even in the Old Testament, He valued moral obedience as the only end for which positive ordinances, such as sacrifices, were instituted-as of more importance than a mere external ritual obedience (1Sa 15:22; Ps 50:8, 9; 51:16; Isa 1:11, 12; Mic 6:6-8; Mt 9:13; 12:7).

knowledge of God-experimental and practical, not merely theoretical (Ho 6:3; Jer 22:16; 1Jo 2:3, 4). "Mercy" refers to the second table of the law, our duty to our fellow man; "the knowledge of God" to the first table, our duty to God, including inward spiritual worship. The second table is put first, not as superior in dignity, for it is secondary, but in the order of our understanding.

Matthew Henry's Concise Commentary

6:4-11 Sometimes Israel and Judah seemed disposed to repent under their sufferings, but their goodness vanished like the empty morning cloud, and the early dew, and they were as vile as ever. Therefore the Lord sent awful messages by the prophets. The word of God will be the death either of the sin or of the sinner. God desired mercy rather than sacrifice, and that knowledge of him which produces holy fear and love. This exposes the folly of those who trust in outward observances, to make up for their want of love to God and man. As Adam broke the covenant of God in paradise, so Israel had broken his national covenant, notwithstanding all the favours they received. Judah also was ripe for Divine judgments. May the Lord put his fear into our hearts, and set up his kingdom within us, and never leave us to ourselves, nor suffer us to be overcome by temptation.