The second is the agreement of those qualified to decide and bind, and this has two forms:

The first is that the preceding caliph appoints those qualified to decide and bind. For example, he may say: “So-and-so, so-and-so, so-and-so, and so-and-so shall consult concerning the caliph.” This is what Umar ibn al-Khattab, may Allah be pleased with him, did. Umar selected six of the Companions with whom the Messenger of Allah, peace and blessings be upon him, died pleased (1), and he confined the caliphate to them, on the condition that they choose from among themselves whomever they chose.

The second is that the caliph leaves no bequest of the caliphate to anyone—that is, he does not designate anyone for the caliphate. Rather, after him the people gather and appoint a caliph. This is permissible, because the matter is entrusted to the people: if they choose one of their number to be their caliph, his caliphate is thereby established.

The third is seizure by force. If a person overpowers a caliph, gains control over him, and kills or imprisons him, so that his caliphate is definitively ended, and then takes control of the caliphate, he becomes caliph. The people must pledge allegiance to him and obey him, for if they were to oppose him in that situation, it would result in evil, corruption, bloodshed, and violations of honor far greater than that involved in pledging allegiance to this man.

The imam, or caliph, bears immense responsibilities, for he is responsible for all those over whom Allah has placed him in authority in all their public affairs. Their private affairs, however, do not fall under his authority—unless they are matters that must be addressed, such as enjoining what is right and forbidding what is wrong. And