John Trapp on Job 40:21

Verſe 21. He lyeth under the ſhady trees] Vatablus readeth the words queſtion-wiſe thus,Sic R. Levi. & Kimchi. Lyeth he under the ſhady trees in the covert of the reeds and fens? No ſuch matter, he is too big to be ſhaded by trees, neither can reeds and fens cover him. But Ariſtotle tells us, That he loves to lye by the banks of Rivers beſet with trees,Debiſt. anim. l. 9. c. 46 Plin. lib. 8. c. 10. as being naturally hot, and bred in hot Countries: and yet he is impatient of cold and winter. And therefore when Hannibal brought many Elephants out of Africa into Italy, they all periſhed in the cold Alps, except only that one whereupon Hannibal himſelf rode.

In the covert of the reed and fens] Hence Cardinus ſaith, That the Elephant is of a Swiniſh nature,Ad calorem frangendum craſſo caeno per. funduntur. Plin. delighted with mud and mire. And Gulielmus Pariſienſis applyeth, Behemoth in the fens, to the divel in ſenſual hearts. He ſleepeth in moiſt places, ſaith he; that is, in thoſe that lye melting in ſinful pleaſures and delights: therefore Luke 11. it is ſaid, that he walketh in dry places, ſeeking reſt, but finding none: and Ezek 47.11. when the waters of the Sanctuary overflowed, the miry places could not be healed.