and Basra, compiling the Quran into a single volume, establishing the register of stipends, and other such measures.

The Messenger of Allah, may Allah bless him and grant him peace, prescribed the Ramadan night prayers for his community and led them in congregation for several nights. During his lifetime, people prayed both in groups and individually. However, he did not regularly gather them into a single congregation, lest these prayers become obligatory for them. When he died, may Allah bless him and grant him peace, the revealed law became settled.

When ʿUmar—may Allah be pleased with him—became caliph, he gathered them behind a single imam. The one who gathered them was Ubayy ibn Kaʿb, who assembled the people for these prayers at the command of ʿUmar ibn al-Khattāb—may Allah be pleased with him. ʿUmar was one of the rightly guided caliphs, concerning whom the Prophet, may Allah bless him and grant him peace, said:

“Adhere to my Sunnah and the Sunnah of the rightly guided caliphs after me. Bite firmly upon it with your back teeth.”

That is, the molars, because they exert the greatest force.

In Sahīh Muslim, Ibn ʿUmar is reported to have said:

“The prayer during travel is two rakʿahs. Whoever rejects the Sunnah has disbelieved.”

That is, whoever believes that two rakʿahs do not suffice for a traveller has disbelieved.

The second aspect concerns consistently departing, in acts of worship, from the practice consistently observed by the Messenger of Allah, may Allah bless him and grant him peace. This is an innovation by the agreement of the imams, even if someone supposes that his addition contains some good. An example is the introduction by some earlier people of the call to prayer and the call to commence prayer for the two Eid prayers. They were forbidden to do so, and the imams of the Muslims disapproved of it, just as