I am thy servant, give me understanding. Here the prayer of the preceding verse is repeated. The repetition shows how ardently he wished the blessing prayed for, and how earnest and importunate he was in pleading with God for it. By the words he expresses still more plainly in what way it is that God teaches his own people -- that he does so by illuminating with sound knowledge their understandings, which otherwise would be blind. It would profit us little to have the divine law sounding in our ears, or to have it exhibited in writing before our eyes, and to have it expounded by the voice of man, did not God correct our slowness of apprehension, and render us docile by the secret influence of his Spirit. We are not to suppose that David advances any meritorious claims before God when he boasts of being his servant. Men, indeed, commonly imagine that when we are previously well prepared, God then adds new grace, which they term subsequent grace. But the Prophet, so far from boasting of his own worth, rather declares how deep the obligations were under which he lay to God. It is not in the power of any man to make himself a servant of the Most High, nor can any man bring anything of his own as a price with which to purchase so great an honor. Of this the Prophet was well aware. He knew that there is not one of the whole human family who is worthy of being enrolled among that order; and therefore he does nothing more than adduce the grace he had obtained, as an argument that God according to his usual way would perfect what he had begun. In a similar manner he speaks in Psalm 116:6, "I am thy servant and the son of thine handmaid:" in which place it is abundantly manifest that he does not boast of his services, but only declares that he is one of the members of the Church.

I am thy servant - See the notes at Psalm 116:16.
Give me understanding, that I may know thy testimonies - Since I am thy servant, instruct me in the knowledge of thy will. As I desire to obey thee, show me what will be acceptable obedience, or what thou dost require in order to acceptable service. This is a prayer of piety. A man who sincerely desires to obey God will make it a first point to ascertain what is his will, or what will constitute true obedience.

I am thy servant - See on Psalm 119:94 (note).

I am thy servant,.... Not only by creation, but by grace; and as he had a work to do, he desires to know what it was; and as it was proper he should know his Master's will, he applies to him for it; using this as an argument, that he was his servant, devoted to his service, and willing to perform it to the best of his knowledge and ability; and therefore prays,
give me understanding, that I may know thy testimonies; the Scriptures, which testify of the will of God; which are only rightly understood by those who have their understandings opened and enlightened; or have an understanding given them, that they may understand them, so as to receive and embrace the doctrine, and do the precepts of them: and such an understanding is the gift of God, and owing to his powerful and efficacious grace; see Luke 24:45.