all muslim jurists, no matter what school they belong to or what region they come from, and no matter whether their schools have continued to exist till today or ceased to exist, maintain that referring to the sunnah and abiding by it is part and parcel of islam. all of them, whether they adopt the reasoning approach or stick to texts, refer to the sunnah and adhere to it whenever it becomes clear to them.
here are some examples reported by al-baihaqi to affirm this fact:
i refer to the qur'an, and if i do not find in it what i search for, then i refer to the sunnah; in case i fail to find what i seek in either, then i refer to the statements of the companions, freely acting upon or leaving any of their opinions. but, i do not give precedence to the opinions of others over the companions' opinions. when it comes to the opinions of ibrahim, ash-sha`bi, ibn sirin, al-hasan, `ataa', and ibn al-musayeb, etc., then these are people who conducted ijtihad (independent juristic reasoning) and, so do i.
why imams do not act upon certain hadiths
based on the above, it is utterly inconceivable that a school of fiqh or a leading jurist deliberately disregards an authentic, clear hadith. it is to be noted that by "authentic," i mean that the hadith is authentic from the point of view of the jurist concerned; that is, the jurist himself believes that it is authentic. similarly, by "clear," i mean that the meaning of the hadith is clear for the jurist concerned.
this is what imam ibn taymiyyah focused on in his brief yet valuable book raf` al-malam `an al-a'immah al-a`lam (proving the blamelessness of the leading imams). in this book, he defended leading jurists against some literalist and hasty people who accused scholars of abandoning the sunnah and not conforming to its provisions. he said,
let it be known that none of the widely accepted imams of the ummah would intentionally disobey the messenger of allah (peace and blessings be upon him) by disregarding any part of his sunnah, minor or major. indeed, they are in full and categorical agreement over the obligation of following the messenger. they also agree that opinions of anyone other than the prophet are subject to acceptance or rejection. however, should a specific opinion of any of them be found to contradict an authentic hadith, there must be an excuse for him to do so. the excuses are of three types:
first: the jurist's belief that the hadith is not authentic.
second: the jurist's belief that the hadith does not indeed tackle the issue at hand.
third: the jurist's belief that the ruling referred to in the hadith is abrogated [by another text].
these three types branch into more other excuses.
for example, a jurist may believe that certain provisions or acts of the sunnah were not meant for legislation but rather were merely natural acts made by the prophet in his capacity as a human being, or practiced by him by the way of habit.
also, some provisions could be considered by a jurist to be meant not for general legislation; rather, they were just legal verdicts issued by the prophet in his capacity as a judge in response to special cases, or they were special commands for the muslims issued by the prophet in his capacity as the leader of the ummah on the time. examples for such controversial provisions include hadiths like, "if anyone brings barren land into cultivation, it belongs to him" (abu dawud), "anyone who killed an enemy and has a proof of that, will posses his spoils" (al-bukhari and muslim), and other hadiths over which jurists differed due to their differences in determining to which category they belong.