Commentaries:
Barnes' Notes
I have sworn - I have solemnly purposed; I have given to this purpose the solemnity and sanction of an oath. That is, I have called God to witness; I have formed the purpose in his presence, and with the consciousness that his eye is upon me. So all who make a profession of religion solemnly vow or swear. They do it in the house of God; they do it in the presence of the Discerner of hearts; they do it at the communion table; they do it at the family altar; they do it in the closet, when alone with God.
And I will perform it - Hebrew, I will establish it, or make it to stand. It shall not be a mere purpose. It shall be accomplished. This also is the resolution of all who make a true profession of religion. It is their intention - their solemn determination - to carry out that vow to its full accomplishment, always, and in every place, while life lasts, and forever. A man who makes a profession of religion, intending "not" to carry out what is fairly implied in such a profession, is a hypocrite. Unless there is a solemn purpose to keep the law of God, and always to keep it - to do what is fairly implied in a profession of religion, and always to do it - to defend the truth according to his best means of knowing it, and always to defend it - he cannot possibly be a sincere friend of God; he cannot be truly a religious man. He cannot be loyal to his country who designs to violate any one of its just laws; he cannot be an obedient child who intends to disobey the laws of a parent.
That I will keep thy righteous judgments - Not implying that there are any of the judgments of God which are not righteous, but meaning to characterize all his judgments or laws as righteous.
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