Sahih Muslim Book 25, Hadith Number 5336.

Chapter : Excellence of changing ugly names to good names.

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.