I have sworn, and I will perform it,.... Or, "I have performed it" (h). The psalmist had not only taken up a resolution in his mind, but he had openly declared with his mouth, and professed in a solemn manner, that he would serve the Lord; he had sworn allegiance to him as his King, and, through divine grace, had hitherto kept it; and hoped he ever should, and determined through grace he ever would; see Psa 119:48; that I will keep thy righteous judgments; the precepts of the word, the ordinances of the Lord, the doctrines of grace; all which are righteous, and to be kept, observed, and held to; though they cannot be perfectly kept unless in Christ the surety. (h) "et statui"; Musculus, Muis; "idque ratum feci et implevi", Michaelis.