To them it was revealed, that not to themselves, but to you, did they minister these things, which now have been announced to you through those who preached the Gospel to you by the Holy Spirit sent out from heaven; which things angels desire to look into.
Which things angels desire to look into ... In emphasizing the greatness of the salvation that has come to Christians, Peter in this affirms that even the angels of heaven are deeply concerned and interested in this salvation; and why not?  For their own number who had sinned, there was no day of grace, no offer of pardon, no opportunity to seek a remedy.  The same verse of the word of God which relates their sin also relates their being cast out of heaven!  No wonder they were interested in this new thing wherein God would forgive sinful and rebellious people!  No greater wonder ever appeared, either in heaven or upon earth!  There is no need to suppose that Peter relied upon the book of Enoch for this information, as alleged by Hart,[39] for everything that he affirmed here is represented typically in the carved figures of the holy angels adorning the mercy seat  (Exodus 25:20ff), and who were represented in just such an attitude of inquisitive wonder as that which Peter mentioned here.  (See short dissertation on The Mercy Seat in this series of commentaries, my Commentary on Hebrews, pp. 190-191.)