The Book of Faith (Kitab Al-Iman)

Muslim :: Book 1 : Hadith 103

It is narrated on the authority of Jarir that he observed: I owed allegiance to the Apostle of Allah (may peace and blessings be upon him) on hearing ( is commands) and obeying (them) and the Prophet) instructed me (to act) as lay in my power, and sincerity and goodwill for every Muslim.