2 Kings 20:9

Ten degrees - literally, “ten steps.” It is not, perhaps, altogether certain whether the “dial of Ahaz” 2 Kings 20:11 was really a dial with a gnomon in the center, and “degrees” marked round it, or a construction fur marking time by means of “steps.” Sundials proper had been invented by the Babylonians before the time of Herodotus; but the instrument here was probably an instrument consisting of a set of steps, or stairs, with an obelisk at the top, the shadow of which descended or ascended the steps according as the sun rose higher in the heavens or declined.

The question as to the mode whereby the return of the shadow was produced is one on which many opinions have been held. Recently, it has been urged that the true cause of the phenomenon was a solar eclipse, in which the moon obscured the entire upper limb of the sun; and it has been clearly shown that if such an occurrence took place a little before mid-day, it would have had the effect described as having taken place - i. e., during the obscuration of the sun’s upper limb shadows would be sensibly lengthened, and that of the obelisk would descend the stairs; as the obscuration passed off the reverse would take place, shadows would shorten, and that of the obelisk would once more retire up the steps. If this be the true account, the miracle would consist in Isaiah’s supernatural foreknowledge of an event which the astronomy of the age was quite incapable of predicting, and in the providential guidance of Hezekiah’s will, so that he chose the “sign” which in the natural course of things was about to be manifested.