Turn again, and tell Hezekiah the captain of my people,.... The king of them, as the Targum:
thus saith the Lord God of David thy father, I have heard thy prayer, I have seen thy tears; See Gill on "Isa 38:5"
behold, I will heal thee; instantly, miraculously; and none but God could heal him, his disease being in its kind mortal, and he had been told from the Lord that he should die:
on the third day thou shalt go up unto the house of the Lord: the temple, to give thanks for his recovery; and this he should do on the third day from thence; so soon should he be well, which would show the cure to be miraculous.