2 Peter 2:4

2:4 For if God did not spare the angels who sinned, but threw them into hell and locked them up in chains in utter darkness, to be kept until the judgment,

Jude 1:6

1:6 You also know that the angels who did not keep within their proper domain but abandoned their own place of residence, he has kept in eternal chains in utter darkness, locked up for the judgment of the great Day.