The Authority of the Sunnah
Al-Ihkam fi Usul al-Ahkam
vol I, pp. 96-108, Dar al-Afaq al-Jadidah, Beirut, 2nd ed., 1983/1402.
by Imam `Ali Ibn Hazm (d. 456 H)
“Since we have clarified [in the previous section] that the Qur’an is the source of reference for laws, we looked into it, and found therein the obligation of obedience to what the Messenger of Allah (peace and blessings be upon him) has ordered us, and we found [Allah] the Mighty, the Majestic therein describing His messenger (peace and blessings be upon him), [translated], “He does not speak of his own desire. It is only an inspiration with which he is inspired.” Q[53:3-4] Thus, it is proved for us thereby that inspiration from Allah, the Mighty the Majestic, to His Messenger, can be divided into two categories: one of them [being] recited inspiration compiled in a miraculous form, which is the Qur’an, and the second [being] narrated inspiration, neither compiled [into a single book] nor of miraculous composition, and that is the narrations which have come from the Messenger of Allah (peace and blessings be upon him), his being the explainer on behalf of Allah, the Mighty the Majestic. Allah, the Exalted, says, [translated], “…in order that you may explain to people what has been sent down to them.” Q[16:44] We found [Allah] the Exalted obligating obedience to this second category as He obliged obedience to the first category, without any difference, for [Allah] the Exalted, has said, [translated], “Obey Allah and obey the Messenger.” Q[5:92 and others]
And, it is authenticated for us, by the text of the Qur’an, that the reports [from the Messenger] are one of the two sources to which reference must be made in case of dispute. [Allah], the Exalted, says, [translated], “So, if you dispute concerning anything, then return it to Allah and the Messenger, if you should believe in Allah and the Last Day.” Q[4:59]
Since Allah has clarified for us that the speech of his Prophet is nothing but total inspiration from Him, and that the Qur’an is inspiration from Him, and also He, the Mighty the Majestic, has said therein, [translated], “Had it been from other than Allah they would surely have found therein much contradiction.” Q[4:82] Hence, it is necessarily proved, by this verse, that the Qur’an and authentic hadith are in agreement; they are one [unit], with no contradiction between them nor disagreement. … [Also] proved by this verse is the invalidity of the words of those who make parts of the Qur’an contradict others, or make some authentic ahadith contradict others, or make the Qur’an and authentic hadith contradict one another. If Allah should bestow upon us ample time, and assist us with assistance from Him, then we shall gather … a compilation of all that ignorant people have thought to be contradiction … and explain … that all of that is one, with no contradiction therein.
“Have you not seen those who were given a portion of the Scripture, summoned to the Book of Allah, and then a group amongst them turns away, averse.” Q[3:23]
“And when they are told, ‘Come to what Allah has sent down, and to the Messenger,’ you see the hypocrites turning away from you in aversion.” Q[4:61]
“Whoever obeys the Messenger has obeyed Allah.” Q[4:80] …
“We have not sent down the Book upon you except in order that you may explain to them that wherein they have differed.” Q[16:64] ….
“It is not for a believing man or woman, when Allah and His Messenger have decreed a matter, that they should have choice in the matter. And whoever disobeys Allah and His Messenger has surely gone clearly astray.” Q[33:36]…
“We have not sent any messenger except to be obeyed, by the permission of Allah.” Q[4:64]
“Whatever the Messenger gives you, take it, and whatever he prohibits you from, desist [from it].” Q[59:7]
“So, let them beware who differ from his command, lest a tribulation smite them, or lest a painful punishment smite them.” Q[24:63]
No two Muslims disagree that what has been authentically conveyed from the Messenger of Allah (peace and blessings be upon him), that he said it, is obligatory to follow it, and that it is an exegesis (tafseer) of the intent of Allah, the Exalted, in the Qur’an, and a specification of that of it which is unspecified. Then, Muslims differed about the manner of determining the authenticity of a narration from him (peace be upon him), after the certain, unequivocal consensus on what we have mentioned….Thereupon, we looked into this, and found that narrations can be classfied into two categories:
 a mass-narrated (mutawatir) narration, which is that transmitted by a multitude after multitude [in each generation, going back] until it reaches the Prophet (peace and blessings be upon him) in this manner. This [type of] narration, no two Muslims disagree on the obligation of accepting, and that it is true, giving certainty of the unseen [which it conveys], for by the like of this [transmission] have we come to know that the Qur’an is that which was brought by the Prophet (peace and blessings be upon him), and by it have we come to know the authenticity of the mission of the Prophet (peace and blessings be upon him), and by it have we come to know the number of rak`ah in each salah, and the number of salats, as well as many things concerning the regulations of zakah and other things whose explanation has not been clarified in the Qur’an. We have talked about this [category of narration] in our book ‘al-Fisal,’ and explained that the proof is established concerning its authenticity, and have explained the manner of [this proof], and that necessity and nature oblige its acceptance, and that is by [this type of narration] that we have come to know of countries we have not seen, and of prophets, scholars, philosophers, kings, events and writings which existed before us. Whoever denies this is like someone who denies that which is perceived by the primary senses – there is no difference – and he is obliged [then] to not affirm that there was a time before him, nor that his father and mother existed before him, nor that he was born from a woman.”
 The second category is what has been reported by single narrators from single narrators. Now, this [category], if it is contiguously narrated by reliable narrators upto the Messenger of Allah (peace and blessings be upon him), is obligatory to act upon, and knowledge also becomes incumbent by it. This is the view of al-Harith ibn Asad al-Muhasibi, and Husayn ibn `Ali al-Karabisi. It was professed also by Abu Sulayman, and Ibn Khuwayz-Mandad mentioned it from Malik ibn Anas.
…. [he then goes on to discuss the reasoning behind this view, later saying of it:]
….this is [the view that] we also profess.”