to cooperate with and support one another; they cooperate in securing benefit and support one another in warding off harm, since no individual can, on his own, secure all that benefits him and ward off all that harms him (1).
Whenever they gather, they must have a leader (2). Thus, the Prophet—peace and blessings be upon him—said: “When three people set out on a journey, let them appoint one of them as their leader” (3). Abū Dāwūd narrated it from Abū Saīd and Abū Hurayra (4).
Imam Ahmad also narrated in the Musnad (5), from Ibn Amr (6)—may Allah be pleased with them both—(7), that the Prophet—peace and blessings be upon him—said: “It is not lawful for three people to be in an open tract of land without appointing one of them as their leader.”
The Prophet—peace and blessings be upon him—thus required that one person be appointed as leader in the small, temporary gathering formed during travel, thereby drawing attention to all other forms of association, which are larger and more enduring. Moreover, Allah Most High has enjoined (8) commanding what is right and forbidding what is wrong, and this cannot be accomplished without power and authority,