Lo now, his strength is in his loins - The inspection of the figure of the hippopotamus will show the accuracy of this. The strength of the elephant is in the neck; of the lion in the paw; of the horse and ox in the shoulders; but the principal power of the river-horse is in the loins; compare Nahum 2:1. This passage is one that proves that the elephant cannot be referred to.
And his force is in the navel of his belly - The word which is here rendered “navel” (שׁריר shârı̂yr) means properly “firm, hard, tough,” and in the plural form, which occurs here, means the “firm,” or “tough” parts of the belly. It is not used to denote the “navel” in any place in the Bible, and should not have been so rendered here. The reference is to the muscles and tendons of this part of the body, and perhaps particularly to the fact that the hippopotamus, by crawling so much on his belly among the stones of the stream or on land, acquires a special hardness or strength in those parts of the body. This clearly proves that the elephant is not intended. In that animal, this is the most tender part of the body. Pliny and Solinus both remark that the elephant has a thick, hard skin on the back, but that the skin of the belly is soft and tender. Pliny says (“Hist. Nat.” Lib. viii. c. 20), that the rhinoceros, when about to attack an elephant, “seeks his belly, as if he knew that that was the most tender part.” So Aelian, “Hist.” Lib. xvii. c. 44; see Bochart, as above.