It is narrated from Sayyiduna Abdur Rahman bin Awf (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "I participated with my uncles—while I was still young—in the Hilf al-Mutayyibeen, which is also called Hilf al-Fudul. I would not like to break this agreement even if I were given red camels in exchange for it."
Imam Zuhri (may Allah have mercy on him) narrates that the Prophet (peace and blessings be upon him) also said: "Every treaty that Islam has made, its severity has only increased, and Islam does not advocate this." However, the Prophet (peace and blessings be upon him) established brotherhood between the Quraysh and the Ansar.
Hadith Referenceمسند احمد / مسند باقي العشرة المبشرين بالجنة / 1655