I am thine, save me. In the first place, he takes encouragement to pray from the consideration, that he is one of God's own stamp and coinage, as we speak. In the second place, he proves that he is God's from the fact of his keeping his commandments. This ought not, however, to be understood as if he boasted of any merit which he possessed; as, in dealing with men, it is customary to adduce something meritorious which we have done as an argument for obtaining what we desire: -- I have always loved and esteemed you, I have always studied to promote your honor and advantage; my service has always been ready at your command. But David rather brings forward the unmerited grace of God, and that alone; for no man, by any efforts of his own, acquires the high honor of being under the protection of God -- an honor which proceeds solely from his free adoption. The blessing which God had conferred upon him is therefore here adduced as an argument why he should not forsake the work which he had commenced. When he affirms, that he was earnestly intent upon the Divine commandments, that also depended upon the Divine calling; for he did not begin to apply his mind to God's commandments before he was called and received into his household. As he desires, in this verse, that the Lord would save him, so, in the next verse, he expresses the need he had of being saved, saying, that the wicked sought for him to destroy him; by which he, at the same time, declares the constancy of his godliness, inasmuch as he then set his mind upon the law of God -- a point worthy of special notice. Those who, at other times, would the forward and willing to follow God, know not to what side to turn themselves when they are assailed by the wicked, and, in that case, are very prone to follow unhallowed counsel. It is therefore a great virtue to do God the honor of resting contented with his promises alone, when the wicked conspire for our destruction, and when, to all human appearance, our life is in jeopardy. To consider God's testimonies is, in this place, equivalent to applying our minds to the word of God, which sustains us against all assaults, effectually allays all fears, and restrains us from following any perverse counsels.

I am thine - All that he had, and was, belonged to God. This is an expression of a fact, and of a purpose: a fact about which he had no doubt; a purpose ever to be the Lord's. This is indicative of the real state of feeling in the heart of a pious man. He feels that he is the Lord's; he has no other desire than to be his forever.
Save me - Deliver me from my enemies; from sin; from hell. As he belonged to God, he prayed that God would save and preserve his own.
For I have sought thy precepts - I feel assured or confident that this has been the aim and purpose of my life. On this ground I plead that thou wilt keep and preserve me. A man who feels assured that he is a friend of God has a right to appeal to him for protection, and he will not appeal to him in vain.

I am thine, save me - He who can say this need fear no evil. In all trials, temptations, dangers, afflictions, persecutions, I am thine. Thy enemies wish to destroy me! Lord, look to thy servant; thy servant looks to thee. O how sovereign is such a word against all the evils of life! I am Thine! therefore save thine Own!

I [am] (c) thine, save me; for I have sought thy precepts.
(c) He proves by effect that he is God's child, because he seeks to understand his word.

I am thine, save me,.... From all troubles and afflictions; from all enemies, temporal and spiritual; from Satan, and his principalities and powers, from sin, and all the wretched consequences of it; from hell wrath, and damnations: salvation from all which is by Christ. And this is a prayer of faith with respect to him, founded upon his interest and property in him; whose he was by choice, by covenant, by gift, by purchase, and by grace: and this is a plea for salvation; thou hast an interest in me, I am one of thine, therefore let me not be lost or perish;
for I have sought thy precepts; to understand them better, and observe them more constantly; and which sense of interest and relation, and of salvation, will influence unto.