Sahih Bukhari Volume 008, Book 079, Hadith Number 708.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 79. Expiation for Unfulfilled Oaths
Narated By â€˜Aisha: That she intended to buy Barira (a slave girl) and her masters stipulated that they would have her Wala'. When 'Aisha mentioned that to the Prophet; he said, "Buy her, for the Wala' is for the one who manumits."