My lips shall speak praise. David now shows in another way than in the preceding verse, how high a privilege he accounted it to be admitted by God among the number of His disciples, and to profit aright in His school, by declaring that, if so privileged, he will hasten forward to render thanks to him with fluent tongue. The word nv, naba, which he employs, is a metaphor taken from the bubbling up of fountains, and accordingly it signifies not simply to speak, but to pour forth speech copiously. As therefore he a little before showed the earnestness of his desire by praying, so now he affirms that his rejoicing will bear testimony that he desires nothing more than to be thoroughly imbued with heavenly truth. He again confirms the doctrine, That the way by which we become truly wise is, first by submitting ourselves to the Word of God, and not following our own imaginations; and, secondly, by God's opening our understanding and subduing it to the obedience of his will. He here joins together both these truths -- namely, that when God has set before us His law, from which we are to learn what, ever is profitable for our welfare, He, at the same time, teaches us inwardly. It were not enough to have our ears stricken with the outward sound, did not God illuminate our minds by the Spirit of understanding, and correct our obduracy by the Spirit of docility. As the labor of teachers is to no purpose until virtue and efficacy has been given to it, so it is also to be noticed that such as are truly taught of God, are not led away from the law and the Scriptures by secret revelations, like some fanatics, who think that they linger still at their A B C, unless disdainfully trampling under foot the Word of God, they fly away after their own foolish fancies.

My lips shall utter praise, when thou hast taught me thy statutes - The sentiment here is the same as in Psalm 119:7. The language is varied, but the meaning here, as in that verse, is, I will praise thee in proportion as I learn thy precepts or thy law. The more I learn of thy will, the more I will praise thee. I shall see more for which to offer praise and adoration, and I shall be more and more inclined to praise and adore time. Each new degree of knowledge will excite a corresponding desire to praise thee. This will be true of all who love God, while this life lasts, and forever. The ever-increasing knowledge of God will excite ever-increasing praise; and as God is infinite and eternal, it follows that the increase of knowledge and of happiness, in those who are saved, will be eternal. These things will go hand in hand forever and ever.

My lips shall utter praise - תהלה tehillah, a song of praise.

My lips shall (b) utter praise, when thou hast (c) taught me thy statutes.
(b) The word means to pour forth continually.
(c) All his prayer and desire is to profit in the word of God.

My lips shall utter praise,.... Like water flowing from a fountain, as the word (m) signifies. The heart of a good man is like a fountain of water, abounding: with good things, and his mouth is a well of life; out of the abundance of grace and good things in his heart his mouth speaks, John 4:14; and particularly his heart is filled with praise and thankfulness for the many blessings of providence and grace enjoyed; his lips show it forth; it comes flowing from him freely and readily, without force and compulsion, largely and plentifully, constantly and continually, and with great vehemence and strength, as streams from a fountain;
when thou hast taught me thy statutes: which is what the psalmist often prays for in this psalm; and signifies he should be very thankful to God for, and should sincerely praise him, could he obtain this favour; see Psalm 119:7.
(m) "profundent", Vatablus, Musculus; "ebullient", Piscator, Gejerus; "scaturiunt", Cocceius; "scaturient", Michaelis.

shall utter--or, "pour out praise" (compare Psalm 19:2); shall cause Thy praises to stream forth as from a bubbling, overflowing fountain.