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.
The passage indeed admits of a twofold meaning; either that the treasure we have in the gospel fills the angels with a desire to see it, as it is a sight especially delightful to them; or that they anxiously desire to see the kingdom of Christ, the living image of which is set forth in the gospel. But the last seems to me to be the most suitable meaning. 