Charles Ellicott Commentary Job 41:20

"Out of his nostrils a smoke goeth, As of a boiling pot and [burning] rushes." — Job 41:20 (ASV)

Out of his nostrils goeth smoke, as out of a seething pot or caldron. —The last word is uncertain: it is the same as was translated in the Authorized Version “hook” at Job 41:2; and taking the same sense here, we may render, as of a seething pot and rushes: that is, a pot made hot with rushes.