The Apostle Peter
1 Peter 1:16ESV·traditional attribution

since it is written, “You shall be holy, for I am holy.”

Matthew Henry Presbyterian @wholebiblehenry

Here the apostle begins his exhortations to those whose glorious state he had before described, thereby instructing us that Christianity is a doctrine according to godliness, designed to make us not only wiser, but better. I. He exhorts them to sobriety and holiness. 1. Wherefore gird up the loins of your mind, etc., Pe1 1:13.

Commenting on 1 Peter 1:13-23

John Gill Reformed Baptist @doctorgill

Because it is written,.... In Lev 11:44. be ye holy, for I am holy: an argument the apostle knew must have weight with these persons, who were chiefly Jews, scattered abroad among the Gentiles, and had a value for the Scriptures of truth; and therefore, as the argument for holiness of life, from the nature and perfections of God, is strong, it must receive additional...

Albert Barnes Presbyterian @notesbybarnes

Verse 16. Because it is written, Be ye holy; for I am holy. . This command was addressed at first to the Israelites, but it is with equal propriety addressed to Christians, as the professed people of compared. The foundation of the command is, that they professed to be his people, and that as his people they ought to be like their God. .