With my lips In this verse he declares that the law of God was not only deeply engraven on his own heart, but that it was his earnest and strenuous endeavor to gain over many of his fellow-disciples into subjection to God. It is indeed a heartless matter to speak of the law of God abstractly, as we see hypocrites do, who talk very fluently about the whole doctrine of godliness, to which they are entire strangers. What the prophet noticed above, respecting the affection of the heart for God's law, he now likewise applies to the lips. And, immediately afterwards, he again establishes the truth of what he had asserted about his cordial and unfeigned endeavors to instruct others; by saying, that he derived no less pleasure from the doctrine of God than from all the riches of the world. He indirectly contrasts his holy love for the law, with which he was inflamed, with the unholy avarice which has taken possession of almost all the world. "As wealth attracts to itself the hearts of mankind, so I have taken more exquisite delight in the progress which I make in the doctrine of godliness, than if I abounded in all manner of riches."

With my lips have I declared - That is, I have openly and publicly made thy words known to others; I have defended and vindicated them.
All the judgments - The word judgments here means the same as statutes or laws: and the idea is, that he had been on the side of those laws, and had endeavored by argument and persuasion to bring others under their influence. How he had done it we are not informed; but we have no reason to suppose that the author of the psalm was a minister of religion, and if not, then we have here an example of what a man who does not claim to be a public teacher may do, and should do, in making known and defending divine truth. Every man is as much bound to do this in his sphere as the minister of religion is in his; and private member's of the church have often an opportunity of doing this to more advantage than the ministers of the gospel possess.
Of thy mouth - With my mouth I speak those things which have proceeded from thine. I speak in thy name; I declare thy truth. It is not my own; it is thine.

With my lips have I declared -
10. He should declare to his own heart, and to all his companions in iniquity, God's judgments against himself and them; that if his longsuffering merely have not made a proper impression on their hearts, they may tremble at his approaching judgments.

With my lips have I declared all the judgments of thy mouth. Not the judgments of his hand, what he executes on an ungodly world; nor the intricate dispensations of his providence; those judgments of his now unsearchable, though before long will be manifest; these the psalmist could not declare: but the revelation of the will of God, what his mouth has uttered, doctrines and precepts of righteousness and truth; these, though David had them in his heart, he did not conceal them from men; but out of the abundant experience he had of them in his heart, his lips spake of them, of their nature and excellency, and usefulness unto others: and whereas he desired to be instructed more and more in them, it was in order to teach them, and declare them to others; even all of them, in the most sincere and impartial manner; see Acts 20:27.