The Book on General Behaviour (Kitab Al-Adab)
Muslim :: Book 25 : Hadith 5336
Zainab, daughter of Umm Salama, reported: My name first was Barra. Allah's Messenger (may peace be upon him) gave me the name of Zainab. Then there entered (into the house of Allah's Prophet as a wife) Zainab, daughter of Jahsh, and her name was also Barra, and he gave her the name of Zainab.