many verses from Sūrat al-Tawbah, in which Allah sets out the details and the severity of that expedition, praises the believers, censures the hypocrites and their failure to join the campaign, and declares His acceptance of repentance from the Prophet, the Emigrants, and the Helpers who followed him in the hour of hardship—together with the three men who had been left behind, once they too repented and returned.

Amid the narratives of these campaigns Allah also reveals verses on jihād: its obligation, its merit, the reward reserved for those who undertake it, and the immediate humiliation and eventual punishment awaiting those who shrink from it. During this same period He continued to send down the legal rulings gradually, in accordance with His wisdom.

• In the ninth year AH—or, according to some reports, the tenth—Allah made the pilgrimage obligatory for the Muslims. Abū Bakr led the people in the pilgrimage of year nine, publicly repudiating the treaties of the idolaters while upholding the covenants of those who had not broken them.

The Prophet ﷺ then performed the Farewell Pilgrimage in year ten, accompanied by virtually the entire Muslim community. By word and deed he taught them the rites of ḥajj and ʿumrah; during it Allah revealed the verses dealing with the pilgrimage and its rulings, and on the Day of ʿArafah He sent down: “Today I have perfected your religion for you, completed My favor upon you, and approved Islam for you as your religion” (al-Māʾidah 3).

From that point onward no branch of beneficial knowledge was left unexplained, for the Qur’an is a clarification of all things: the sciences of fundamentals, the detailed rulings of practice, the sciences of character and etiquette, the sciences of the cosmos—everything humanity will need from that day until the Hour is established. In the Qur’an lies the exposition and the guidance; to it all religious and rational truths are ultimately referred. It is impossible—indeed inconceivable—for any sound knowledge, whether empirically observed or rationally deduced, to contradict anything that the Qur’an has brought, for it is “a revelation from One who is All-Wise, Praiseworthy” (Fussilat 42); “falsehood can approach it neither from before it nor from behind it” (Fussilat 42); “Do they not, then, reflect upon the Qur’an? Had it been from anyone other than Allah, they would surely have found in it much inconsistency” (al-Nisāʾ 82); “Indeed, this Qur’an guides to that which is most upright” (al-Isrāʾ 9); and “Allah speaks the truth, and He guides to the path”.