Psalms 18:21

I have observed and obeyed his precepts, and made mine own will, and passions, and interest stoop to them. And I have not knowingly and wilfully forsaken God, and broken his laws, as wicked men do; which he adds by way of correction and explication, lest the former or following clauses should be interpreted as a profession of such a perfect and sinless righteousness, whereby he might in strict justice be justified by and before God, which he elsewhere utterly disowns, Psalms 130:3, Psalms 143:2, and which David, especially towards the end of his days, (when this Psalm was composed, as the title shows,) could not pretend to without great arrogancy and falsehood, as having been guilty of those great sins of murder and adultery, and many other errors, as he confesseth, Psalms 19:12, and oft elsewhere.