1 Peter 1:12

The Holy Ghost being sent down from heaven, on whom the Angels desire to look. [2] This place is differently expounded. Some refer these words, on whom the Angels desire to look, to Jesus Christ, who was named in the foregoing verse; some to the Holy Ghost, who, being one God with the Father and the Son, the Angels are happy in seeing and loving him. See Estius and the Greek text. (Witham)

[BIBLIOGRAPHY]

In quem desiderant Angeli prospicere. The Greek manuscripts and copies at present have Greek: eis a, in quæ, which is commonly expounded to agree with the mysteries revealed to the prophets, and which the Angels rejoiced and were delighted to see fulfilled by the coming of Christ. It seems as if the ancient interpreter had read Greek: eis o, agreeing with Greek: pneuma, spiritum; or perhaps Greek: eis on, to agree with Greek: theon, understood. These changes of a letter might easily happen. It appears that not only divers Latin interpreters, but also some of the Greek Fathers brought these words to shew the divinity of the Holy Ghost, as St. Athanasius, Epist. i. ad Serap. p. 653. Edit. Ben.