From the International Standard Bible Encyclopedia, 2nd. ed.
NEPHILIM nef׳ǝ- lim [Heb. n p̱ȋlȋm (Gen. 6:4; Nu. 13:33)], AV GIANTS. The etymology of n p̱ȋlȋm is uncertain. The following explanations have been advanced with mixed reception. First, it may derive from the niphal of the verb pālā’, meaning “be extraordinary,” i. e., “extraordinary men.” Second, it may derive from the verb nāp̱al, “fall,” in one of the following senses1) the “fallen ones”- from heaven, i. e., supernatural beings; (2) morally “fallen men”; (3) “those who fall upon,” in the sense of invaders or hostile, violent men; (4) “those who fell by” the sword (cf. Ezk. 32:20f.); (5) “unnaturally begotten men” or bastards (cf. nēp̱el, “abortion” or “miscarriage”). None of these satisfies all scholars, and some consider n p̱ȋlȋm an unexplainable relic from an ancient, now- forgotten language. Contextual information is unfortunately limited to two enigmatic passages.
The Nephilim were apparently people of imposing physical stature when compared with the smaller Hebrews (Nu. 13:33). This particular reference is glossed by a statement which implies that the offspring of Anak in Canaan were descended from the renowned Nephilim of Gen. 6:4. The latter had gained a reputation as notable heroes in the antediluvian period, and apparently persisted after the Flood (w g̱am ’aḥ rȇ- ḵēn). This could have occurred through migration, on the basis of a local Mesopotamian deluge, and in that case would account for their descendants living in Canaan.
The Anakim were a tall people (Dt. 2:21; see Anak) with whom the Rephaim, another pre- Israelite group in Canaan, were compared. The large stature of the individuals composing these groups suggests a condition such as hypertrophy of the long bones of the skeleton, or some other disorder of a genetic variety. This becomes even more likely if the Rephaim were being indicated by the use of a term such as rāp̱ā’ in 1 Ch. 20:6, 8, where genetic mutations are being described (cf. rāp̱ȃ in 2 S. 21:16, 18, 20, 22).
Genesis 6:1- 4, while meaningful to the original recipients, has become obscure with the passing of time. It is impossible to be certain whether the Nephilim were the same as the “mighty men” (gibbȏrȋm) at the end of v. 4, or a separate group that overlapped chronologically. If they were identical, questions are then raised about the “sons of God” which procreated the “mighty men” (see Sons of God [OT]). Some modern scholars have followed ancient Jewish tradition in supposing that the “sons of God” were “fallen ones,” perhaps angels, who mated with women after being cast out of heaven, thereby giving origin to the “mighty ones” (but see J. Morgenstern, HUCA, 14 [1935], 76- 107). Such a view generally presupposes that vv. 1- 4 are an etiological fragment or a “myth” that helps to explain the character of antediluvian wickedness and the consequent need for the Flood.
That the material may conceivably be ancient Semitic historiography that contains important, if obscure, anthropological, demographic, or sociological information is a proposition that seems to be taken seriously only by some conservative scholars. They consequently oppose the “mythical” conception and interpret “sons of God” as a reference to the Sethite line (Gen. 5) or to the nobility (cf. Kline), whose mixed marriages to the “daughters of men” (“men” in a restricted sense as wicked or common people) contributed to a moral decline. They argue that “myth” is inconsonant with the perspective of the Pentateuch, that “angels” are pure in Genesis and sexless in the Bible as a whole (Mt. 22:30), and that people should not be punished (Gen. 6:3) for a sin that is primarily that of angels (v. 2).
Against the claim that “sons of God” (b nȇ hā’ lōhȋm) is always used of angels, it should be noted that the equivalent phrase in Greek described a man (Adam) in Lk. 3:38, as did the comparable expression b nȇ ‘elyȏn (“sons of the Most High”) in Ps. 82:6. The unions would thus appear to be between two human groups, the males being perhaps of the Sethite line and the females possibly constituting neanthropic remnants that were exterminated by the Flood. Whether or not the “mighty men” were actually Nephilim, no particular sin seems to have been attached to their parentage. What was condemned was the violence and corruption that characterized contemporary society (Gen. 6:11f.).
The “demigod” explanation of the Nephilim, so popular in some circles, seems therefore less preferable than a nonmythological, sociological explanation which sees the people described as specifically human groups engaged in relationships of deteriorating social and spiritual quality