O Lord, by these things men live,.... Not by bread only, but by the word of God: by the promise of God, and by his power performing it; and by his favour and goodness continually bestowed; it is in him, and by his power and providence, that they live and move, and have their being, and the continuance of it; and it is his lovingkindness manifested to them that makes them live comfortably and go on cheerfully:and in all these things is the life of my spirit; what kept his soul in life were the same things, the promise, power, and providence of God; what revived his spirit, and made him comfortable and cheerful, was the wonderful love and great goodness of God unto him, in appearing to him, and for him, and delivering him out of his sore troubles.
Ben Melech renders and gives the sense of the words thus; "to all will I declare and say, that in these", in the years of addition (the fifteen years added to his days) "are the life of my spirit"; so Kimchi.
The Targum interprets it of the resurrection of the dead,"O Lord, concerning all the dead, thou hast said, that thou wilt quicken them; and before them all thou hast quickened my spirit:''so wilt thou recover me, and make me to live; or rather, "and" or "for thou hast recovered me, and made me to live"; for the Lord had not only promised it, but he had done it, Isa 38:15, and so the Targum,"and hast quickened me, and sustained me.'