BEHEMOTH bĭ he’ məth (hippopotamus, בְּהֵמוֹת, H990). This is the most common Heb. word for beast (all Eng. VSS). This pl. form occurs nine times in the OT, and in all passages except one it is tr. “beast” or “beasts.” The exception is in Job 40:15 where the context clearly suggests a specific animal, for which most Eng. VSS give the transliteration “behemoth” but RSVmg. has “hippopotamus.” Some Heb. scholars consider that pl. is used here for intensive effect and many commentators agree with RSVmg. The Heb. scholar and zoologist Bodenheimer differs, regarding it as a general expression here also, and refers to its discussion in Job commentary of Tur. Sinai. The passage is largely fig. and the only points which seem clear are that it is aquatic and powerful (v. 23) and eats grass (v. 15). Also there are ancient records of hunting hippos with harpoons and barbed hooks (Diodorus Siculus 37:35). The hippo was certainly known in Biblical times, esp. in Egypt, where its numbers were greatly reduced by the Romans because of the damage done to crops, but it finally disappeared only in the 12th cent. a.d. It had lived in eastern Mediterranean rivers in the Palaeolithic age, but largely disappeared as the climate became drier and rather cooler, but there is evidence of it in the Orontes River (Syria) around 1500 b.c. Though called hippopotamus (river horse) the hippo is most closely related to the pigs, in the even-toed hoofed animals. Technically, therefore, it divides the hoof, but it does not actually chew the cud; however, it has a complex three-chambered stomach to deal with the masses of poorly digestible plant material which it eats.See Beast.
J. A. Wood, Bible Animals (1869), 318-330; F. S. Bodenheimer, Animals and Man in Bible Lands (1960).
International Standard Bible Encyclopedia (1915)
be’-he-moth, be-he’-moth (behemoth: Job 40:15): Apparently the plural of behemah, "a beast," used of domestic or wild animals. The same form, behemoth, occurs in other passages, e.g. De 28:26; 32:24; Isa 18:6; Hab 2:17, where it is not rendered "behemoth" but "beasts." According to some, the word behemoth, occurring in Job 40:15, is not a Hebrew word, the plural of behemah, but a word of Egyptian origin signifying "water ox." This etymology is denied by Cheyne and others. The word has by various writers been understood to mean rhinoceros and elephant, but the description (Job 40:15-24) applies on the whole very well to the hippopotamus (Hippopotamus arnphibius) which inhabits the Nile and other rivers of Africa. Especially applicable are the references to its great size, its eating grass, the difficulty with which weapons penetrate its hide, and its frequenting of streams. "He lieth under the lotus-trees, In the covert of the reed, and the fen. The lotus-trees cover him with their shade; The willows of the brook compass him about." The remains of a fossil hippopotamus of apparently the same species are found over most of Europe, so that it may have inhabited Palestine in early historical times, although we have no record of it. There is a smaller living species in west Africa, and there are several other fossil species in Europe and India. The remains of Hippopotamus minutus have been found in enormous quantities in caves in Malta and Sicily.
For an elaborate explanation of behemoth and leviathan (which see) as mythical creatures, see Cheyne, EB, under the word