Albert Barnes Commentary Isaiah 38:16

"O Lord, by these things men live; And wholly therein is the life of my spirit: Wherefore recover thou me, and make me to live." — Isaiah 38:16 (ASV)

O Lord, by these things men live - The design of this and the following verses is evidently to declare the goodness of God, and to celebrate His praise for what He had done. The phrase ‘these things,’ refers evidently to the promises of God and their fulfillment; and the idea is that people are sustained in the land of the living only by such gracious interventions as he had experienced. It was not because people had any power of preserving their own lives, but because God intervened in time of trouble, and restored to health when there was no human prospect that they could recover.

And in all these things - In these promises, and in the divine intervention.

Is the life of my spirit - I am alive solely because of these things.

So wilt thou recover me - Or so You have recovered me; that is, You have restored me to health.