1 Enoch 21:10
7 And from there I went to another place, which was still more horrible than the former, and I saw a horrible thing: a great fire there which burned and blazed, and the place was cleft as far as the abyss, being full of great descending columns of fire: neither its extent or magnitude could I see, nor could I conjecture. 8 Then I said: 'How fearful is the place and how terrible to look upon!' 9 Then Uriel answered me, one of the holy angels who was with me, and said unto me: 'Enoch, why do you have such fear and fright?' And I answered: 'Because of this fearful place, and because of the spectacle of the pain.' 10 And he said to me: 'This place is the prison of the angels, and here they will be imprisoned forever.'
1 Peter 3:19
15 But set Christ apart as Lord in your hearts and always be ready to give an answer to anyone who asks about the hope you possess. 16 Yet do it with courtesy and respect, keeping a good conscience, so that those who slander your good conduct in Christ may be put to shame when they accuse you. 17 For it is better to suffer for doing good, if God wills it, than for doing evil. 18 Because Christ also suffered once for sins, the just for the unjust, to bring you to God, by being put to death in the flesh but by being made alive in the spirit. 19 In it he went and preached to the spirits in prison, 20 after they were disobedient long ago when God patiently waited in the days of Noah as an ark was being constructed. In the ark a few, that is eight souls, were delivered through water.
Notes and References
"... One of the greatest cruxes of all the passages in the New Testament is the material found in 1 Peter 3 about the spirits in prison. One of the keys to unraveling this text’s meaning is recognizing its intertextual echoes not only of Genesis 6:1–4 but also of the later interpretations of Genesis 6 in 1 Enoch. ... Commentators have long known that there is some connection between 1 Enoch and what is said in 1 Peter 3:18–22, but the exact connections have been vigorously debated. Indeed, so vigorous has the debate been that some have dubbed this passage in 1 Peter the most difficult one in the whole New Testament to understand ... None of this is a surprise when we recognize that 1 Enoch is influential in various of these Jewish Christian eschatological works, for instance Jude not merely refers to the text of 1 Enoch in verses 4, 6, and 13, he even cites it in verses 14–15 of his discourse. 2 Peter as well is directly dependent on 1 Enoch at 2 Peter 2:4 and 3:13 ..."
Witherington, Ben Torah Old and New: Exegesis, Intertextuality, and Hermeneutics (pp. 397-401) Fortress Press, 2018