I have sworn and I will confirm it, That I will keep Your righteous ordinances.
NASB95
I have sworn an oath and confirmed it, to keep your righteous rules.
ESV
I have sworn, and I will perform it, that I will keep thy righteous judgments.
KJV

The blessing of the guidance of the Lord's word naturally strengthens our resolution to walk in its path. And as if a simple resolution would prove too weak, the Psalmist strengthens it with an oath. No more, as if an oath was hardly sufficient security, be seconds it again with a firm resolution—I have sworn, and I will perform it. 'There shall be but one will between me and my God; and that will shall be His, not mine.' Some timid Christians, under a morbid sense of their own weakness, would shrink from this solemn engagement. And some, perhaps, may have burdened their consciences with unadvised or self-dependent obligations. Still, however, when it is a free-will offering, it is a delightful service, well-pleasing to God. Such it was in the days of Asa, when "all Judah rejoiced at the oath: for they had sworn with all their heart, and sought Him with their whole desire; and He was found of them." Vows under the law were both binding and acceptable. Nor are they less so—in their spirit at least—under "the perfect law of liberty." A holy promise originating in serious consideration, and established by a more solemn obligation, so far from being repugnant to the liberty of the gospel, appears to have been enjoined by God Himself; no, His people are described as animating each other to it, as to a most joyous privilege; as a renewed act of faith and daily dedication.

Yet we would warn the inconsiderate Christian not to entangle his conscience by multiplied vows (as if they were—like prayer—a component part of our daily religion); nor by perpetual obligation—whether of restraint or of extraordinary exercises; nor by connecting them with trifles—thus weakening the deep solemnity of the purpose. Christian simplicity must be their principle. Our engagements to God must be grounded on His engagements to us. His faithfulness—not ours—must be our confidence. There is no innate power in these obligations; and except they be made in self-renouncing dedication, they will only issue in despondency and deeper captivity in sin.

But the inconsiderateness of the unwary is no legitimate argument against their importance. If Jephthah was entangled in a rash and heedless vow, David manifestly enjoyed the "perfect freedom" of the "service" of his God, when "binding his soul with a bond" equally fixed, but more advised, in its obligation. And have we; with "the vows of God upon us," baptismal vows—perhaps also confirmation or sacramental vows—found our souls brought into bondage by these solemn engagements? Does not a humbling sense of forgetfulness suggest sometimes the need of a more solemn engagement? And may we not thus secure our duty without being ensnared by it? Have not covenanting seasons often restrained our feet from devious paths, and quickened our souls in His service? Daily, indeed, do we need "the blood of sprinkling" to pardon our innumerable failures, and the Spirit of grace to strengthen us for a more devoted obligation. But yet in dependence upon the work and Spirit of Christ, often have these holy transactions realized to us a peace and joy, that leads us to look back upon such times and seasons of favored enjoyment. "If," therefore, "we sin" in a "perpetual backsliding" from these engagements, it is still our privilege without presumption to believe, that "we have an advocate with the Father, Jesus Christ the righteous; and He is the propitiation for our sins." And as for necessary grace, there is One who has said, "My grace is sufficient for you;" and that One has given no less a proof of His interest in us, than by dying for us. May we not therefore trust, that He will "perfect that which concerns us;" that He will "work all our works in us" "to will and to do of His good pleasure?"

Perhaps however "a messenger of Satan "may "buffet us." "You have broken your bond; now will it be worse with you than before." But did not Jesus die for sins of infirmity, and even of presumption? Does every failing annul the marriage covenant? So neither does every infirmity or backsliding dissolve our covenant with God. Was our faithfulness the basis of this covenant? Rather, does not "the blood of this covenant" make constant provision for our foreseen unfaithfulness? And does not our gracious God overrule even our backsliding to establish a more simple reliance upon Himself, and a more circumspect and tender walk before Him?

But let us take a case of conscience. A Christian has been drawn away from a set season of extraordinary devotion by some unforeseen present duty, or some unlooked-for opportunity of actively glorifying God. Has he then broken his obligation? Certainly not. It was, or ought to have been, formed with an implied subserviency to paramount duty. It cannot, therefore, be impaired by any such providential interference. Yet let it not be a light matter to remove a free-will offering from the altar. Let godly care be exercised to discover the subtle indulgence of the flesh in the service of God. Let double diligence redeem the lost privilege of more immediate and solemn self-dedication. In guarding against legal bondage, let us not mistake the liberty of the flesh for the liberty of the Gospel. Let us be simple and ready for self-denying service; and the Lord our God will not fail to give "some token for good."

"Come" then, my fellow-Christian, "and let us join ourselves to the Lord in a perpetual covenant, never to be forgotten" by God: never to be forsaken by us. Let each of us renew our surrender, "O Lord, truly I am Your servant;" I offer myself to You: "You have loosed my bonds;" oh! bind me to Yourself with fresh bonds of love, that may never be loosed. Glad am I that I am anything—though the lowest of all; that I have anything—poor and vile as it is—capable of being employed in Your service. I yield myself to You with my full bent of heart and will, entirely and forever; asking only, that I may be "a vessel for the Master's use."

Under the influence of the clear light of knowledge he had firmly made up his mind, and solemnly declared his resolve in the sight of God. Perhaps mistrusting his own fickle mind, he had pledged himself in sacred form to abide faithful to the determinations and decisions of his God. Whatever path might open before him, he was sworn to follow that only upon which the lamp of the word was shining. The Scriptures are God's judgments, or verdicts, upon great moral questions; these are all righteous, and hence righteous men should be resolved to keep them at all hazards, since it must always be right to do right. Experience shows that the less of covenanting and swearing men formally enter upon the better, and the genius of our Savior's teaching is against all unnecessary pledging and swearing; and yet under the gospel we ought to feel ourselves as much bound to obey the word of the Lord as if we had taken an oath so to do. The bonds of love are not less sacred than the fetters of law. When a man has vowed, he must be careful to "perform it"; and when a man has not vowed in so many words to keep the Lord's judgments, yet is he equally bound to do so by obligations which exist apart from any promise on our part—obligations founded in the eternal fitness of things, and confirmed by the abounding goodness of the Lord our God. Will not every believer own that he is under bonds to the redeeming Lord to follow his example, and keep his words? Yes, the vows of the Lord are upon us, especially upon such as have made profession of discipleship, have been baptized into the thrice-holy name, have eaten of the consecrated memorials, and have spoken in the name of the Lord Jesus. We are enlisted, and sworn in, and are bound to be loyal soldiers all through the war. Thus, having taken the word into our hearts by a firm resolve to obey it, we have a lamp within our souls as well as in the Book, and our course will be light unto the end.