Unto whom So searching; it was revealed, that not unto themselves, but unto us Not so much for their own benefit as for ours, to whose time the accomplishment of their prophecies was reserved; they did minister the things which are now reported unto you Performed the office of foretelling the things, the accomplishment whereof has been declared unto you. In other words, that they did not so much by their predictions serve themselves or that generation, as they have served us, who now enjoy what they only saw afar off. With the Holy Ghost sent down from heaven Confirmed by the inward powerful testimony of the Holy Ghost, as well as the mighty effusion of his miraculous gifts. Which things the angels desire to look into To obtain a more perfect insight into, and knowledge of, as being matters of their admiration and delight, because in them the manifold wisdom of God is displayed, and by them the salvation of men is procured and effected, which they rejoice in. The expression, the angels desire to look into, is literally, to stoop down to. “But stooping being the action of one who desires to look narrowly into a thing, it properly means to look attentively. The omission of the article before αγγελοι, angels, renders the meaning more grand. Not any particular species of angels, but all the different orders of them, desire to look into the things foretold by the prophets, and preached by the apostles. See Ephesians 3:10. This earnest desire of the angels to contemplate the sufferings of Christ, was emblematically signified by the cherubim placed in the inward tabernacle, with their faces turned down toward the mercy-seat, Exodus 25:20. To that emblem there is a plain allusion in the word παρακυψαι here, to stoop. The apostle's meaning is, If our salvation, and the means by which it is accomplished, are of such importance as to merit the attention of angels, how much more do they merit our attention, who are so much interested in them!” Macknight.
Here is a beautiful gradation: prophets, righteous men, kings, desired to hear and see the things which Christ did and taught, Matthew 13:17; but what the Holy Ghost taught concerning Christ, the very angels long to understand.