Albert Barnes Commentary Job 41:19

"Out of his mouth go burning torches, And sparks of fire leap forth." — Job 41:19 (ASV)

Out of his mouth go burning lamps – The word “lamps” here is probably used to denote torches or firebrands. The animal is described as in pursuit of its prey on land, and the description is exceedingly graphic and powerful.

Its mouth is then open, its jaws are distended, its breath is thrown out with great violence, and its blood is inflamed; the animal seems to vomit forth flames.

The description is, of course, to be regarded as figurative. It is the kind of description one would likely give upon seeing a fierce animal pressing on in pursuit of its prey.

And sparks of fire leap out – There is an appearance like sparks of fire. The animal, with an open throat highly inflamed, seems to breathe forth flames. This figure is a common one applied to a warhorse. Thus, Ovid:

“From their full racks the generous steeds retire,
Dropping ambrosial foam and snorting fire.”
Dr. Good

The same thing is remarked by Achilles Tatius, concerning the hippopotamus: “With open nostrils, and breathing smoke like fire (πυρώδη καπνόν purōdē kapnon) as from a fountain of fire.”

And in Eustathius it is said, “They have an open nostril, breathing forth smoke like fire from a furnace” – πυρώδη καπνόν, ὡς ἐκ καμίνου πνέοντα purōdē kapnon, hōs ek kaminou pneonta. See Bochart.