Jude 1:5-7

Now I desire to remind you, though you know all things once for all, that the Lord, after saving a people out of the land of Egypt, subsequently destroyed those who did not believe. And angels who did not keep their own domain, but abandoned their proper abode, He has kept in eternal bonds under darkness for the judgment of the great day, just as Sodom and Gomorrah and the cities around them, since they in the same way as these indulged in gross immorality and went after strange flesh, are exhibited as an example in undergoing the punishment of eternal fire.