Ramban

THE NEPHILIM. Rashi comments: “[They were called nephilim because] they fell (naphlu) and caused the downfall (hipilu) of the world.” This is found in Bereshith Rabbah. The masters of language say that they [the Nephilim] were so called because the heart of man fell from fear of them. The same applies to the word ha’eimim. means terror. The Eimim thus induced terror into the hearts of those who saw them. IN THOSE DAYS. Rashi comments: “in the days of the generation of Enosh. AND ALSO AFTER THAT. Although they witnessed the destruction of the generation of Enosh when the ocean rose and flooded a third of the world, still they did not humble themselves and take a lesson from them.” Rabbi Abraham ibn Ezra explained: “also after the flood, since the sons of Anak were of the family of bnei ha’elohim.” If so, we must say that either the wives of Noah’s sons were of their [the Nephilim’s] descendants and resembled them or that ibn Ezra will accept the statement of the Rabbi who advanced the interpretation that Og (Genesis 14:13); i.e., escaped from the flood. escaped from the flood, to which Rabbi Abraham will add that others too escaped with him [since the verse states: “The ‘Nephilim’ — (in the plural) — were in the earth…and also after that”, which Ibn Ezra interprets as meaning after the flood]. The correct interpretation appears to me to be that Adam and his wife are called bnei ha’elohim because they were G-d’s handiwork and He was their father; they had no father besides Him. And he [Adam] begot many children, as it is written, And he begot sons and daughters. Now these men, first to be born of a father and mother, were of great perfection in height and strength because they were born in the likeness of their father, as it is written concerning Seth, And he [Adam] begot a son in his own likeness, after his image., Verse 3. And it is possible that all the children of the first generations — Adam, Seth, Enosh — were called bnei ha’elohim because these three men were in the likeness of G-d. But then the worship of idols commenced, and there came upon men a weakness and slackness. And so they said in Bereshith Rabbah: “This is the book of the generations of Adam. Are not the first ones toldoth (offspring)! But what are they? [They are in the image and likeness of] G-d. They raised a question before Aba Kohen Bardela: ‘Adam, Seth, Enosh?’ At first, he was silent, but then he said to them: ‘Up to here [Seth] they were in the image and likeness of G-d; after that, Kenan, vexers.’”. Enosh’s son was Kenan (Above, 5:9), which name is interpreted as having the same root as the word kanteir (he who makes himself disagreeable). Now when men began to multiply and daughters were born to them, the men of these first generations were in their strength, and because of their great desire they would choose the beautiful women of tall stature and good health. Now first Scripture tells that by force they took them unto themselves as wives, and afterwards it tells that they came in a promiscuous manner to the daughters of men who were not of that high degree, and the matter was not known until they begot children for them, and everyone recognized that they were not the offspring of other people but that they had been born to these bnei ha’elohim because these children were very tall. They were, however, inferior to their fathers in height and strength, [This is the meaning of the name Nephilim — inferior ones], just as the word Nephilim is used in the expression: I am not ‘nophel’ (inferior) to you. Still they were mighty men in comparison with the rest of the people. And Scripture tells that this happened in the first generation to those who were called bnei ha’elohim because they were of absolute perfection, and it is they who caused the daughters of men to beget nephilim (inferior ones); and also after that, for the nephilim themselves begot nephilim from them. The meaning of the expression, that were of old, is that after the flood, the men, upon seeing the mighty, would remember these nephilim and say: “There have already been mightier men than these in the ages which were before us.” They were the men of renown in all generations afterward. This is a fitting explanation of this chapter. But the Midrash of Rabbi Eliezer the Great, in the chapters concerning the angels that fell from their place of holiness in heaven — as is mentioned in the Gemara of Tractate Yoma — fits into the language of the verse more than all other interpretations. But it would necessitate delving at length into the secret of this subject.