Job 40:21 - Ellicott's Commentary On The Whole Bible

He lieth under the shady trees. — If this description applies to any one animal, it seems on the whole more appropriate to the elephant than the hippopotamus. No doubt the judgment of critics has been biased by their pre-conceived notions about the circumstances under which they suppose the Book of Job to have been written; and the author was more likely, it is thought, to have been acquainted with the river-horse of Egypt than with the elephant of India, though, to be sure, elephants abound also in Africa, and may very well have been known to the writer of Job from that quarter, if the other is less likely.