Then came the word of the LORD to Isaiah, saying,

Jamieson-Fausset-Brown Bible Commentary

4. In 2Ki 20:4, the quickness of God's answer to the prayer is marked, "afore Isaiah had gone out into the middle court, the word of the Lord came to him"; that is, before he had left Hezekiah, or at least when he had just left him, and Hezekiah was in the act of praying after having heard God's message by Isaiah (compare Isa 65:24; Ps 32:5; Da 9:21).

Matthew Henry's Concise Commentary

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 2Ki 20:1-11.