The Apostle Peter
1 Peter 2:10ESV·traditional attribution

Once you were not a people, but now you are God’s people; once you had not received mercy, but now you have received mercy.

John Calvin Reformed @genevareformer

10 Which in time past were not a people He brings for confirmation a passage from Hosea, and well accommodates it to his own purpose. For Hosea, after having in God’s name declared that the Jews were repudiated, gives them a hope of a future restoration.

Matthew Henry Presbyterian @wholebiblehenry

I. The apostle here gives us a description of Jesus Christ as a living stone; and though to a capricious wit, or an infidel, this description may seem rough and harsh, yet to the Jews, who placed much of their religion in their magnificent temple, and who understood the prophetical style, which calls the Messiah a stone (Isa 8:14; Isa 28:16), it would appear very elegant and proper. 1.

Commenting on 1 Peter 2:4-12

John Gill Reformed Baptist @doctorgill

Dearly beloved, I beseech you,.... The apostle, from characters of the saints, and which express their blessings and privileges, with great beauty, propriety, and pertinency, passes to exhortations to duties; he addresses the saints under this affectionate appellation, "dearly beloved", to express his great love to them, and to show that what he was about to exhort them to sprung from sincere and hearty affection...