| Barnes' Notes on the Bible I cried unto thee - I called upon thee in trouble. Save me, and I shall keep thy testimonies - Margin, "That I may keep." The correct rendering is, "I will keep." The idea is, that if God would interpose and save him, he "would" henceforward faithfully keep the law of God: It is one of the designs of affliction to lead people to make such vows as this. They are commonly made on beds of sickness, alike by the religious and the irreligious; the saint and the sinner. How often, alas, are they forgotten even by the friends of God! How seldom are they remembered at all by the sinner when he is raised up from the verge of the grave, and restored again to health!
Gill's Exposition of the Entire BibleI cried unto thee; save me,.... In his distress he cried and prayed to the Lord; and this was a principal and leading petition, that he would "save" him out of all his troubles and afflictions, and out of the hands of all his enemies; and with a temporal, spiritual, and eternal salvation which he knew he was able to do, and none else; and I shall keep thy testimonies; such salvation will affect my heart, and the sense of it influence and engage me to have the utmost regard to the word of God, its truths and doctrines, precepts and ordinances, so as carefully to observe them.
Geneva Study BibleI cried unto thee; save me, and I shall keep thy testimonies.
King James Translators' Notesand I...: or, that I may keep
Matthew Henry's Concise Commentary119:145-152 Supplications with the whole heart are presented only by those who desire God's salvation, and who love his commandments. Whither should the child go but to his father? Save me from my sins, my corruptions, my temptations, all the hinderances in my way, that I may keep thy testimonies. Christians who enjoy health, should not suffer the early hours of the morning to glide away unimproved. Hope in God's word encourages us to continue in prayer. It is better to take time from sleep, than not to find time for prayer. We have access to God at all hours; and if our first thoughts in the morning are of God, they will help to keep us in his fear all the day long. Make me lively and cheerful. God knows what we need and what is good for us, and will quicken us. If we are employed in God's service, we need not fear those who try to set themselves as far as they can out of the reach of the convictions and commands of his law. When trouble is near, God is near. He is never far to seek. All his commandments are truth. And God's promises will be performed. All that ever trusted in God have found him faithful.
Matthew Henry's Whole Bible CommentaryVerses 145-146 Here we have, I. David's good prayers, by which he sought to God for mercy; these he mentions here, not as boasting of them, or trusting to any merit in them, but reflecting upon them with comfort, that he had taken the appointed way to comfort. Observe here, 1. That he was inward with God in prayer; he prayed with his heart, and prayer is acceptable no further than the heart goes along with it. Lip-labour, if that be all, is lost labour. 2. He was importunate with God in prayer; he cried, as one in earnest, with fervour of affection and a holy vehemence and vigour of desire. He cried with his whole heart; all the powers of his soul were not only engaged and employed, but exerted to the utmost, in his prayers. Then we are likely to speed when we thus strive and wrestle in prayer. 3. That he directed his prayer to God: I cried unto thee. Whither should the child go but to his father when any thing ails him? 4. That the great thing he prayed for was salvation: Save me. A short prayer (for we mistake if we think we shall be heard for our much speaking), but a comprehensive prayer: "Not only rescue me from ruin, but make me happy." We need desire no more than God's salvation (Ps. 50:23) and the things that accompany it, Heb. 6:9. 5. That he was earnest for an answer; and not only looked up in his prayers, but looked up after them, to see what became of them (Ps. 5:3): "Lord, hear me, and let me know that thou hearest me." II. David's good purposes, by which he bound himself to duty when he was in the pursuit of mercy. "I will keep thy statutes; I am resolved that by thy grace I will;" for, if we turn away our ear from hearing the law, we cannot expect an answer of peace to our prayers, Prov. 28:9. This purpose is used as a humble plea (v. 146): "Save me from my sins, my corruptions, my temptations, all the hindrances that lie in my way, that I may keep thy testimonies." We must cry for salvation, not that we may have the ease and comfort of it, but that we may have an opportunity of serving God the more cheerfully. | 
