The Prophet—peace and blessings be upon him—said: “I have been commanded to fight the people until they say, ‘There is no deity worthy of worship except Allah, and I am the Messenger of Allah.’” He then cited the rest of the hadith. This is faith professed by the tongue—an obligatory and binding utterance.

As for faith through fulfilling what has been enjoined upon the bodily limbs, thereby confirming what the heart believes and the tongue professes, Allah Most High says: “O you who believe, bow and prostrate” [al-Hajj: 77], up to His words, “so that you may succeed” [al-Baqara: 189]. Allah Most High also says: “Establish prayer and give zakat” [al-Baqara: 43], in several places in the Quran. Likewise, fasting is prescribed for the entire body, and jihad is prescribed through the body and all the bodily limbs.