John Gill's Exposition of the Whole Bible
Proverbs 13:6
Righteousness keepeth [him that is] upright in the way,.... Men of uprightness and integrity, whose hearts are sincere in the ways of God; the principle of grace and righteousness in them keeps them in those ways, and will not suffer them to turn aside into crooked paths; the word of righteousness, the doctrine of the Gospel, is a means of preserving them from sin, and of keeping them in the right way; particularly the doctrine of Christ's righteousness, and justification by it, is a great antidote against sin, and a powerful motive and incentive to the performance of good works, and all the duties of religion: it engages men to observe every command of Christ, to walk in all his ways; and is a great preservative from false doctrine and antichristian worship;
but wickedness overthroweth the sinner; it is the cause of his utter overthrow, of his being punished with everlasting destruction. It is, in the Hebrew text, "sin" b itself; the sinner is so called, because he is perfectly wicked, as Jarchi observes; he is nothing but sin, a mere mass of sin and corruption. Aben Ezra renders it, "the man of sin"; and it may be well applied to him, who is emphatically called so, and is likewise the son of perdition; who, for his wickedness, will be overthrown and destroyed at the coming of Christ, and with the brightness of it, 2 Thessalonians 2:3.
b חטאת "peccatum"; Montanus, Vatablus, Cocceius, Michaelis; "lapsationem", Schultens.