Here is, 1. David's firm and fixed resolution to live a holy life: I will keep the commandments of my God. Bravely resolved! like a saint, like a soldier; for true courage consists in a steady resolution against all sin and for all duty. Those that would keep God's commandments must be often renewing their resolutions to do so: "I will keep them. Whatever others do, this I will do; though I be singular, though all about me be evil-doers, and desert me; whatever I have done hitherto, I will for the future walk closely with God. They are the commandments of God, of my God, and therefore I will keep them. He is God and may command me, my God and will command me nothing but what is for my good." 2. His farewell to bad company, pursuant to this resolution: Depart from me, you evil-doers. Though David, as a good magistrate, was a terror to evil-doers, yet there were many such, even about court, intruding near his person; these he here abdicates, and resolves to have no conversation with them. Note, Those that resolve to keep the commandments of God must have no society with evil-doers; for bad company is a great hindrance to a holy life. We must not choose wicked people for our companions, nor be intimate with them; we must not do as they do nor do as they would have us do, Psa 1:1; Eph 5:11.

Thou puttest away all the wicked of the earth like dross,.... Which is of no worth and value, useless and unprofitable; which is cast into the fire, and separated from the choice metal. This expresses the character and state of wicked men; who are of no account with God, are of no profit and advantage to him; nor to men, but harmful and pernicious; are cast into the fire of God's judgments here, and into everlasting burnings hereafter; and will be separated from the righteous, and have no part and lot with them: these seem to be hypocrites also, who have made a show of being gold and silver, when they were nothing but dross; and being reprobate silver, were rejected of God as such;

therefore I love thy testimonies; which discover such persons when brought to be tried by them; and which require purity of heart and life, and caution against evil ways and evil men, and are a means of preserving from them.