He brought the shadow ten degrees backward - We cannot suppose that these ten degrees meant ten hours; there were ten divisions of time on this dial: and perhaps it would not be right to suppose that the sun went ten degrees back in the heavens, or that the earth turned back upon its axis from east to west, in a contrary direction to its natural course. But the miracle might be effected by means of refraction, for a ray of light we know can be varied or refracted from a right line by passing through a dense medium; and we know also, by means of the refracting power of the atmosphere, the sun, when near rising and setting, seems to be higher above the horizon than he really is, and, by horizontal refraction, we find that the sun appears above the horizon when he is actually below it, and literally out of sight: therefore, by using dense clouds or vapors, the rays of light in that place might be refracted from their direct course ten, or any other number of degrees; so that the miracle might have been wrought by occasioning this extraordinary refraction, rather than by disturbing the course of the earth, or any other of the celestial bodies.

The dial of Ahaz - See the note on 2 Kings 9:13, and the observations and diagram at the end of this chapter.

And Isaiah the prophet cried unto the Lord,.... Or prayed, as the Targum; and was very earnest in prayer, that what Hezekiah had desired might be granted:

and he brought the shadow ten degrees backward, by which it had gone down in the dial of Ahaz; Ben Gersom understands it not of the sun itself, but of the shadow of it only; See Gill on Isaiah 38:8.

Isaiah then prayed to the Lord, and the Lord "turned back the shadow (caused it to go back) upon the sun-dial, where it had gone down, on the sundial of Ahaz, ten degrees backward." אחז מעלות cannot be understood, as it has been by the lxx, Joseph., Syr., as referring to a flight of steps at the palace of Ahaz, which was so arranged that the shadow of an object standing near indicated the hours, but is no doubt a gnomon, a sun-dial which Ahaz may have received from Babylonia, where sun-dials were discovered (Herod. ii. 109). Nothing further can be inferred from the words with regard to its construction, since the ancients had different kinds of sun-dials (cf. Martini Abhandlung von den Sonnenuhren der Alten, Lpz. 1777). The word מעלות steps in the literal sense, is transferred to the scala, which the shadow had to traverse both up and down upon the disk of the sun-dial, and is used both to denote the separate degrees of this scala, and also for the sum-total of these scala, i.e., for the sun-dial itself, without there being any necessity to assume that it was an obelisk-like pillar erected upon an elevated place with steps running round it (Knobel), or a long portable scale of twice ten steps with a gnomon (Gumpach, Alttestl. Studien, pp. 181ff.). All that follows from the descent of the shadow is that the dial of the gnomon was placed in a vertical direction; and the fact that the shadow went ten degrees down or backward, simply presupposes that the gnomon had at least twenty degrees, and therefore that the degrees indicated smaller portions of time than hours. If, then, it is stated in 2 Kings 20:8 of Isaiah that the sun went back ten degrees, whereas the going back of the shadow had been previously mentioned in agreement with our text, it is self-evident that the sun stands for the shining of the sun which was visible upon the dial-plate, and which made the shadow recede. We are not, of course, to suppose that the sun in the sky and the shadow on the sun-dial went back at the same time, as Knobel assumes. So far as the miracle is concerned, the words of the text do not require that we should assume that the sun receded, or the rotation of the earth was reversed, as Eph. Syr. and others supposed, but simply affirm that there was a miraculous movement backward of the shadow upon the dial, which might be accounted for from a miraculous refraction of the rays of the sun, effected by God at the prophet's prayer, of which slight analoga are met with in the ordinary course of nature.

(Note: As, for example, the phenomenon quoted by several commentators, which was observed at Metz in Lothringen in the year 1703 by the prior of the convent there, P. Romuald, and other persons, viz., that the shadow of a sun-dial went back an hour and a half. - The natural explanation of the miracle which is given by Thenius, who attributes it to an eclipse of the sun, needs no refutation. - For the different opinions of the earlier theologians, see Carpzov, Apparat. crit. p. 351ff.)

This miraculous sign was selected as a significant one in itself, to confirm the promise of a fresh extension of life which had been given to Hezekiah by the grace of God in opposition to the natural course of things. The retrograde movement of the shadow upon the sun-dial indicated that Hezekiah's life, which had already arrived at its close by natural means, was to be put back by a miracle of divine omnipotence, so that it might continue for another series of years.

And Isaiah the prophet cried unto the LORD: and he brought the shadow ten degrees backward, by which it had gone down in the {h} dial of Ahaz.

(h) Which was set at the top of the stairs that Ahaz had made.

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.

dial: Heb. degrees

20:1-11 Hezekiah was sick unto death, in the same year in which the king of Assyria besieged Jerusalem. A warning to prepare for death was brought to Hezekiah by Isaiah. Prayer is one of the best preparations for death, because by it we fetch in strength and grace from God, to enable us to finish well. He wept sorely: some gather from hence that he was unwilling to die; it is in the nature of man to dread the separation of soul and body. There was also something peculiar in Hezekiah's case; he was now in the midst of his usefulness. Let Hezekiah's prayer, see Isa 38. interpret his tears; in that is nothing which is like his having been under that fear of death, which has bondage or torment. Hezekiah's piety made his sick-bed easy. O Lord, remember now; he does not speak as if God needed to be put in mind of any thing by us; nor, as if the reward might be demanded as due; it is Christ's righteousness only that is the purchase of mercy and grace. Hezekiah does not pray, Lord, spare me; but, Lord, remember me; whether I live or die, let me be thine. God always hears the prayers of the broken in heart, and will give health, length of days, and temporal deliverances, as much and as long as is truly good for them. Means were to be used for Hezekiah's recovery; yet, considering to what a height the disease was come, and how suddenly it was checked, the cure was miraculous. It is our duty, when sick, to use such means as are proper to help nature, else we do not trust God, but tempt him. For the confirmation of his faith, the shadow of the sun was carried back, and the light was continued longer than usual, in a miraculous manner. This work of wonder shows the power of God in heaven as well as on earth, the great notice he takes of prayer, and the great favour he bears to his chosen.