Volume 8 · Book 73 · Hadith 212
Narrated Abu Huraira: Zainab's original name was "Barrah," but it was said' "By that she is giving herself the prestige of piety." So the Prophet changed her name to Zainab.
— Sahih Bukhari, Volume 8, Book 73: Good Manners and Form (Al-Adab), Hadith #212