John Wesley on 2 Kings 20:11

Degrees - These degrees were lines in the dial: but whether each of these lines or degrees noted an hour, or half an hour, or a quarter of an hour, is uncertain. But the sun itself went back, and the shadow with it. This miracle was noted by the Babylonians, who, having understood that it was done for Hezekiah's sake, sent to enquire into the truth and manner of it, 2Chron 32:31. Of Ahaz - Which Ahaz had made in the king's palace. This dial he mentions, because the truth of the miracle might be best and soonest discovered there, this dial possibly being visible out of the king's chamber, and the degrees being most distinct and conspicuous in it.