1 Enoch 7:2
1 And all the others them took wives for themselves, each choosing one for himself, and they began to unite with them and defiled themselves with them. They taught them sorcery, spells, and the art of extracting medicinal substances from plants. 2 The women became pregnant and gave birth to enormous giants, whose height was three thousand ells. 3 These giants consumed everything humans produced. And when humans could no longer support them, 4 the giants turned against them and devoured mankind.
3 Maccabees 2:4
3 For you, the creator of all things and the governor of all, are a just Ruler, and you judge those who have done anything in insolence and arrogance. 4 You destroyed those who in the past committed injustice, among whom were even giants who trusted in their strength and boldness, whom you destroyed by bringing on them a boundless flood. 5 You consumed with fire and sulfur the people of Sodom who acted arrogantly, who were notorious for their vices; and you made them an example to those who should come afterward.
Notes and References
"... 1 Enoch 7:3-5 ... In later literature, the giants' wickedness and God's punishment of it become proverbial, more so than the example of their fathers, the watchers. In Jubilees 7:22-23 the present passage is paraphrased with an emphasis on their violence. Sirach 16:7 speaks of their rebellion. They are one of a series of examples of God's not pardoning or showing pity to sinners. Similarly, 3 Maccabees 2:4 mentions them (as in Sirach 16:7, followed immediately by Sodom) in a catalog of sinners who were punished. Another such catalog of sinners appears in the Damascus Document 2:17-3:12. The giants and their fathers are said to have fallen, perhaps a play on the name nephilim. Wisdom of Solomon 14:6 mentions in passing that they were arrogant. In 1 Baruch 3:26-28 the giants are the example par excelence, and the only example, of folly .. the passage appears to depend both on Genesis 6:4 and the Enochic version with its reference to their destruction ..."
Nickelsburg, George W. E. A Commentary on the Book of 1 Enoch Chapters 1-36, 81-108 (p. 186) Fortress Press, 2001