Vs. 21 — You rebuke the proud—the cursed, Who stray from Your commandments.

Thomas Manton:

… of erring from God’s commandments. There is an erring out of frailty, and an erring out of obstinacy.
1. An erring out of frailty; and so David saith, Ps. 119:176, ‘I have gone astray like a lost sheep;’ and again, Ps. 19:12, ‘Who can understand his errors?’ This is not meant here of every failing and slip, every sin of ignorance and incogitancy; no, nor every act of rebellion and perverseness of affection which may be found in the children of God. Though there be pride in all sins against knowledge and light, that kind of sinning is interpretatively a confronting of God, a despising of his commandments; as David is said to do, 2 Sam. 12:9, pro hic et nunc, for the time; the will of the creature is set up against the creator; yet this is not the erring here spoken of.
2. There is an erring out of obstinacy, impenitency, and habitual contempt of the lawgiver. This is spoken of, Ps. 95:10, ‘It is a people that do err in their hearts.’ To err in mind is bad, to err out of ignorance; but it is a people that stubbornly refuse to walk in the ways God hath enjoined them. Some err out of simple nescience, ignorance, or mistake, or else through the cloud with which some present temptation overcasts the mind. These err in their minds, but others err in their hearts, that care not for, or do not desire to hear of, their duty to God. A man that erreth out of ignorance can say, ‘Lord, I know not;’ but those that err in their heart, they say, ‘We desire not the knowledge of thy ways,’ Job 21:14; they do not only fall into sin, but love to continue in it. The apostle speaks of ‘ungodly deeds ungodly committed,’ Jude 15. The matter of sin is not so much to be regarded as the manner, with what heart it is done, ungodly committed, with contempt of God. Now, such contemners of God and his law are here described, as all obstinate and impenitent sinners are. (Manton, T. (1872). The Complete Works of Thomas Manton (Vol. 6, pp. 194–195). London: James Nisbet & Co.)

Prayer:

O’ God, You rebuke the proud—the cursed, who stray from Your commandments. I pray to You this hour because it pleased You to deliver me from my proud and obstinate heart, removing my heart of stone and giving me a heart of flesh that chases after Christ Jesus. Forgive me for the pride that I still wrestle with each day. It is vile in every sense and opposes the Christ. I want to grow and slay the giant of pride. Its arrogance taunts me at times and deceives me. I want the jewel of humility to reign in my heart. Conform this servant of Christ to Your commandments.