5 Go and say to Hezekiah, Thus saith Jehovah, the God of David thy father: I have heard thy prayer, I have seen thy tears: behold, I will add to thy days fifteen years. 6 And I will deliver thee and this city out of the hand of the king of Assyria, and I will defend this city. 7 And this [shall be] the sign to thee from Jehovah, that Jehovah will do this thing that he hath spoken: 8 behold, I will bring again the shadow of the degrees which hath gone down with the sun on the dial of Ahaz, ten degrees backward. So the sun returned on the dial ten degrees, by which it had gone down.
Matthew Henry's Commentary on Isaiah 38:5-8
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.