My lips shall utter a hymn, when thou shalt teach me thy justifications.

“"My lips shall burst forth praise: when You have taught me Your righteousnesses" [Psalm 119:171]. We know how God teaches those who are docile unto God. For every one who has heard from the Father and has learned, comes unto Him "who justifies the ungodly:" so that he may keep the righteousnesses of God not only by retaining them in his memory, but also by doing them. Thus does he who glories, glory not in himself, but in the Lord, [1 Corinthians 1:31] and burst forth praise.”

“I have gone astray like a lost sheep,.... In desert places, as it is the nature of sheep to do (o). A sheep he was, a sheep of Christ, given him by the Father; known by him, and that knew him; knew his voice, and followed him; a sheep of his hand, and of his pasture; one of the lost sheep of the house of Israel, who had been lost in Adam, though recovered by grace; and had gone astray before conversion, but now returned to the Shepherd and Bishop of souls; and since conversion had gone astray from the Shepherd and fold, from the word and precepts of it, through inadvertence, the prevalence of corruption, the snares of the world, and the temptations of Satan; which he both deprecates and owns, Psa 119:10; though it may be understood, as it is by many interpreters, of his being forced, by the persecutions of his enemies, to wander from the courts of God, and from place to place: seek thy servant; as a shepherd does his sheep when gone astray, which will not return of itself unless sought after: thou art my Shepherd, as if he should say, look me up, restore my soul; suffer me not to wander from thee, and go astray from thy word and ordinances: and when he calls himself his servant, it carries in it an argument for being looked up and sought out; since he was his servant, not by nature, but by grace; not by force, but willingly; he was his and devoted to his service. And another follows: for I do not forget thy commandments; he retained a knowledge of them, an affection for them, and a desire to observe them; though he had gone astray from them, either in a criminal way, through the power and prevalence of sin, or against his will, through the force of persecution. (o) So Aristotle observes, Hist. Animal. l. 9. c. 3. the same word that is used for feeding sheep is also translated "wander", Num. xiv. 33. so "errant" is used by Virgil for feeding with security, Bucolic. Eclog. 2, Vid. Servium in ib. Next: Psalms Chapter 120”