The Pulpit Commentary - Job 41:21
His breath kindleth coals, and a flame goeth out of his mouth . All the representations of dragons breathing smoke and flames, found in the myths and sagas of so many countries, probably rest upon the observed fact of ,team or spray streaming forth from the mouth and widely opened nostrils of the crocodile. The steam has seemed to be smoke, and smoke has naturally suggested flame and fire. read more
The Pulpit Commentary - Job 41:20
Out of his nostrils goeth smoke, as out of a seething pot or caldron; rather, as from a seething pot and rushes ; i.e. as from a pot heated by burning rushes. read more