Sahih Bukhari Volume 003, Book 037, Hadith Number 491.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 37. Transference of a Debt from one Person to Another (Al-Hawaala)
Narated By Asim : I heard Anas bin Malik, "Have you ever heard that the Prophet said, 'There is no alliance in Islam?' " He replied, "The Prophet made alliance between Quarish and the Ansar in my house."