At an Islamic State checkpoint on the southern outskirts of Kirkuk stands a billboard proclaiming, “The Islamic State: A Caliphate in Accordance with the Prophetic Method.” Search Twitter for the phrase in Arabic and you will see it’s popular with the jihadist set, who quote and swap pictures of it incessantly. (In one such picture, a little boy holds the slogan above his head.)
The Islamic State’s spokesman, Abu Muhammad al-Adnani, is also fond of the phrase. Just months before the Islamic State’s declaration of the caliphate, Adnani invoked it to rebut al-Qaeda’s claim that the Islamic State had become too extreme: “A state of Islam rules by your Book and the tradition of your Prophet and fights your enemies. So reinforce it, honor it, aid it, and establish it in the land. Make it a caliphate in accordance with the prophetic method.”
The phrase comes from a prophecy attributed to the Prophet Muhammad, who explains how religious authority will become increasingly secular and abusive after his death until the caliphate is restored.
“Prophethood will be among you as long as God intends, and then God will take it away if He so wills. Then there will be a caliphate according to the prophetic method. It will be among you as long as God intends, and then God will take it away if He so wills. Then there will be a mordacious monarchy. It will be among you as long as God intends, and then God will take it away if He so wills. Then there will be a tyrannical monarchy. It will be among you as long as God intends, and then God will take it away if He so wills. Then there will be a caliphate in accordance with the prophetic method.”
When the Islamic State declared a caliphate in June, Adnani reminded the world of the prophecy uttered “by the tongue of the prophet,” proclaiming “nothing remains after the elimination of these borders, the borders of humiliation, and the breaking of the idol, the idol of nationalism, except the caliphate in accordance with the prophetic method.” Signage and stationary further reinforce the claim that the Islamic State’s nightmarish bureaucracy fulfills Muhammad’s prophecy. An Islamic State soldier in Iraq’s Nineveh province wears a patch emblazoned with the slogan, and official Islamic State letterhead includes the words.
According to the story of the prophecy, Muhammad fell silent after he predicted the restoration of the caliphate. Many Sunni jihadists and other apocalypticists have interpreted the Prophet’s silence to mean the caliphate will be restored at the end of time. Among them was al-Qaeda firebrand Anwar al-Awlaki, who believed Muslims would reestablish the caliphate in accordance with the prophetic method after they had finally vanquished the infidels. Awlaki theorized that the “massive air power invented by humanity today” would annihilate any caliphate established before this final victory. The Islamic State is testing that theory today.
 Abu Muhammad al-`Adnani, “Ma kana hadha manhajuna wa-lan yakun,” 17 April 2014.