(23) The fire ran along upon the ground.--Heb., fire walked earthwards. Kalisch and Knobel understand by this mere ordinary lightning, but Aben-Ezra, Canon Cook, and others think that the phenomenon was such as our Version well expresses. There is no doubt that the electric fluid occasionally takes a form which has something of permanency, continuing several seconds, or even minutes, either stationary or with a slow motion. Appearances of this kind have been called "fire-balls," and indicate an excessive electrical disturbance, involving great peril to life and property. If the expression "fire walked earthwards" does not imply anything of this kind, yet the peculiar phrase of Exodus 9:24 would seem to do so.

Verse 23. - Moses stretched forth his rod. In the last set of three plagues, the earthly agent was Moses (Exodus 9:10; Exodus 10:13, 22), whose diffidence seems to have worn off as time went on, and he became accustomed to put himself forward. Thunder and hail. Thunder had not been predicted; but it is a common accompaniment of a hail-storm, the change of temperature produced by the discharge of electricity no doubt conducing to the formation of hailstones. The fire ran along upon the ground. Some very peculiar electrical display seems to be intended - something corresponding to the phenomena called "fireballs," where the electric fluid does not merely flash momentarily, but remains for several seconds, or even minutes, before it disappears.

9:22-35 Woful havoc this hail made: it killed both men and cattle; the corn above ground was destroyed, and that only preserved which as yet was not come up. The land of Goshen was preserved. God causes rain or hail on one city and not on another, either in mercy or in judgment. Pharaoh humbled himself to Moses. No man could have spoken better: he owns himself wrong; he owns that the Lord is righteous; and God must be justified when he speaks, though he speaks in thunder and lightning. Yet his heart was hardened all this while. Moses pleads with God: though he had reason to think Pharaoh would repent of his repentance, and he told him so, yet he promises to be his friend. Moses went out of the city, notwithstanding the hail and lightning which kept Pharaoh and his servants within doors. Peace with God makes men thunder-proof. Pharaoh was frightened by the tremendous judgment; but when that was over, his fair promises were forgotten. Those that are not bettered by judgments and mercies, commonly become worse.And Moses stretched forth his rod toward heaven,.... The same which Aaron had made use of before, but was now in the hand of Moses, and whose rod it properly was:

and the Lord sent thunder and hail, and the fire ran along upon the ground, hot thunderbolts, which struck their flocks, Psalm 78:48 and hail which fell so thick and weighty as to destroy both men and cattle, and break trees in pieces, and spoil the corn, the grass, and the tender herb; and fire, that is lightning, which descended so low, and in such quantities, as ran along the ground, and consumed all it met with. Artapanus (g), an Heathen writer, who speaks of this storm of hail, says, that Moses, besides the hail, caused earthquakes by night, so that those that escaped the earthquakes were taken away by the hail, and those that escaped the hail perished by the earthquakes, which he says overthrew all the houses, and most of the temples:

and the Lord rained hail upon the land of Egypt; upon Egypt, where rain was not common, and on all the land of Egypt, when in some parts of it it was scarce known, and hail as thick as rain; ice, snow, and hail, are most rarely if ever seen there, the air not being cold enough for the production of them (h). This was the Lord's immediate doing, when there was no likelihood of it, nor any appearance of second causes concurring to produce it, and came at the exact time he had foretold it should; all which were very extraordinary.

(g) Apud Euseb. Praepar. Evangel. l. 9. c. 27. p. 435, 436. (h) Vid. Scheuchzer. Physica Sacra, vol. 1. p. 139.