8 Behold, I will bring again the shadow of the degrees, which is gone down in the sun dial  of Ahaz, ten degrees backward. So the sun returned ten degrees, by which degrees it was gone down.
8 I will make the shadow cast by the sun go back the ten steps it has gone down on the stairway of Ahaz.' " So the sunlight went back the ten steps it had gone down.
8 Behold, I will make the shadow cast by the declining sun on the dial of Ahaz turn back ten steps." So the sun turned back on the dial the ten steps by which it had declined.
8 Watch for this: As the sun goes down and the shadow lengthens on the sundial of Ahaz, I'm going to reverse the shadow ten notches on the dial.'" And that's what happened: The declining sun's shadow reversed ten notches on the dial.
8 Behold, I will bring the shadow on the sundial, which has gone down with the sun on the sundial of Ahaz, ten degrees backward." So the sun returned ten degrees on the dial by which it had gone down.
8 I will cause the sun's shadow to move ten steps backward on the sundial of Ahaz!'" So the shadow on the sundial moved backward ten steps.
Matthew Henry's Commentary on Isaiah 38:8
Commentary on Isaiah 38:1-8
(Read Isaiah 38:1-8)
When we pray in our sickness, though God send not to us such an answer as he here sent to Hezekiah, yet, if by his Spirit he bids us be of good cheer, assures us that our sins are forgiven, and that, whether we live or die, we shall be his, we do not pray in vain. See 2 Kings 20:1-11.