Psalms 19:9

“The fear of the Lord [is] clean, etc.] Still the word of God is intended, which teaches men to fear the Lord; gives a full account of the worship of God, which is often meant by the fear of God; it instructs in the matter and manner of worship; and nothing more powerfully engages to serve the Lord with reverence and godly fear than the Gospel does: and this is “clean”; and the doctrines of it direct to the blood of Christ, which cleanses from all sin, and to the righteousness of Christ, the fine linen, clean and white; the promises of it put the saints on cleansing themselves from all filthiness of flesh and spirit; and the whole of it is the word of truth, by which God and Christ sanctify…”

“The fear of the Lord - The word rendered fear in this place - יראה yir'âh - means properly fear, terror, Jonah 1:10; then, reverence, or holy fear, Psalms 2:11; Psalms 5:7; and hence, reverence toward God, piety, religion - in which sense it is often used. Compare Proverbs 1:7; Job 28:28; Isaiah 11:2. Hence, by metonymy, it means the precepts of piety or religion. It is used evidently in this sense here, as referring to revelation, or to revealed truth, in the sense that it promotes proper reverence for God, or secures a proper regard for his name and worship. Is clean - The word used here - טהור ṭâhôr - means properly clear, pure, in a physical sense, as opposed to filthy, soiled; then,…”

“The fear - The law and word of God, because it is both the object and the rule, and the cause of holy fear. Clean - Sincere, not adulterated with any mixture. Constant and unchangeable, the same for substance in all ages. Judgments - God's laws are frequently called his judgments, because they are the declarations of his righteous will, and as it were his judicial sentence by which he expects that men should govern themselves, and by which he will judge them at the last day. Psalms 19:12”

“The fear: Psa 34:11-14, Psa 36:1, Psa 115:13; Gen 22:12, Gen 42:18; Sa1 12:24; Kg1 18:3, Kg1 18:4, Kg1 18:12; Neh 5:15; Pro 8:13; Act 10:22; Rom 3:10-18 enduring: Psa 111:10, Psa 112:1-6 judgments: Psa 10:5, Psa 36:6, Psa 72:1, Psa 72:2, Psa 119:7, Psa 119:39, Psa 119:62, Psa 119:75, Psa 119:106, Psa 119:137, Psa 119:138, Psa 119:142, Psa 119:160, Psa 119:164; Psa 147:19; Exo 21:1; Deu 4:8; Isa 26:8; Rom 2:2, Rom 11:22; Rev 15:3, Rev 16:7, Rev 19:2 true: Heb. truth Psalms 19:10”