Here is, 1. The representation David makes of the sorrowful condition he was in: I am afflicted very much, afflicted in spirit; he seems to mean that especially. He laboured under many discouragements; without were fightings, within were fears. This is often the lot of the best saints; therefore think it not strange if sometimes it be ours. 2. The recourse he has to God in this condition; he prays for his grace: "Quicken me, O Lord! make me lively, make me cheerful; quicken me by afflictions to greater diligence in my work. Quicken me, that is, deliver me out of my afflictions, which will be as life from the dead." He pleads the promise of God, guides his desires by it, and grounds his hopes upon it: Quicken me according to thy word. David resolved to perform his promises to God (Psa 119:106) and therefore could, with humble boldness, beg of God to make good his word to him.

Thy testimonies have I taken as an heritage for ever,.... The Scriptures, which testify of Christ and of his grace, and of the mind and will of God, are a portion of themselves; and a goodly heritage they are, better than thousands of gold and silver, preferable to all worldly inheritances; as they have been to many, who have forsaken all for Christ and his Gospel. These, like an inheritance, have been transmitted from father to son, from one age of the church to another, in successive generations; nor shall they depart from her, nor from her seed and seed's seed, from henceforth and for ever; they are an inheritance which will continue for ever, Deu 33:4. These David chose and took, as for his counsellors, so for his portion and inheritance; and a wise and good choice he made; he chose the good part that should never be taken away; his reason for it follows:

for they are the rejoicing of my heart; the doctrines in them, the promises of them, when read or heard explained, gave him a sensible pleasure; revived his heart, and cheered his spirits, supported him under all his troubles, and caused him to go on his way rejoicing; see Jer 15:16.