Albert Barnes Commentary Job 1:16

"While he was yet speaking, there came also another, and said, The fire of God is fallen from heaven, and hath burned up the sheep and the servants, and consumed them; and I only am escaped alone to tell thee." — Job 1:16 (ASV)

While he was yet speaking - All this indicates the rapidity of the movement of Satan, and his desire to overwhelm Job with the suddenness and greatness of his calamities. The object seems to have been to give him no time to recover from the shock of one form of trial before another came upon him. If an interval had been given him, he might have rallied his strength to bear his trials; but afflictions are much more difficult to be borne when they come in rapid succession. It is not a very uncommon occurrence, however, that the righteous are tried by the rapidity and accumulation as well as the severity of their afflictions. It has passed into a proverb that “afflictions do not come alone.”

The fire of God - Margin, “A great fire;” evidently meaning a flash of lightning, or a thunderbolt. The Hebrew is “fire of God;” but it is probable that the phrase is used in a sense similar to the expression, “cedars of God,” meaning lofty cedars, or “mountains of God,” meaning very high mountains. The lightning is probably intended; compare (Numbers 16:35); see the note at (Isaiah 29:6).

From heaven - From the sky, or the air. So the word heaven is often used in the Scriptures; see the notes at (Matthew 16:1).

And has burnt up the sheep - That lightning might destroy herds and men, no one can doubt, though the fact of their being actually consumed or burned up may have been an exaggeration of the very frightened messenger. The narrative leads us to believe that these things were under the control of Satan, though by the permission of God. His power over the lightnings and the winds (Job 1:19) may serve to illustrate the declaration that he is the Prince of the power of the air (Ephesians 2:2).