I add: Imām Abū Muḥammad Ibn Ḥazm has likewise examined this issue thoroughly in his valuable work Iḥkām al-Aḥkām fī Uṣūl al-Aḥkām, published in Egypt in eight volumes. Whoever wishes to verify the consensuses that some people are so fond of citing should consult it, for it is one of the finest books of legal theory, solidly supported by proofs from the Qur’an and the Sunnah, unlike those works that are built on nothing more than bare assertion.

6 – The obligation to confine oneself to eleven rak‘ahs and the evidence for it

It has become evident to every rational person, on the basis of explicit reports, that no authentic narration from any Companion establishes twenty rak‘ahs for the tarāwīḥ prayer, while it is firmly confirmed that ʿUmar—may Allah be pleased with him—ordered it to be performed as eleven rak‘ahs, and that the Prophet ﷺ himself never prayed it except as eleven rak‘ahs. All of this prepares the way for us to state that adhering to this number and not exceeding it is obligatory, in obedience to his ﷺ saying:

“…Whoever among you lives after me will see much discord. Therefore, hold fast to my Sunnah and the Sunnah of the rightly guided caliphs; cling to it with your molars. Beware of newly invented matters, for every innovation is misguidance.”

Another wording adds, “and every misguidance is in the Fire.” ⦗86⦘