Know Oh Muslim that the Madhab of every single one of us supposed to be the authentic Sunnah. In a Hadeeth reported in Ibn Majah on the authority of Irbaad Ibn Sariyah the Prophet (Salallahu alaihi wa sallam) said: “Upon you is what you know to be of my Sunnah and the Sunnah of the Khulafa”. Meaning that the Muslims have to follow what is authentic from the Sunnah of the Messenger (Salallahu alaihi wa sallam) since he also said as reported in Saheeh Muslim: “There will be a people who will speak about matters which neither you or your forefathers know therefore beware of them and let them beware”. Upon this note Shaikh Muhammad Ibn Salih Al Uthaimeen made the following statement in the book: As Sahwah Al Islameeyah:
We find that many people follow books that are authored according to their Madhabs, and they say: My Madhab is so and so! Even if one was to tell a person and says to him: The Prophet (Salallahu alaihi wa sallam) said so and so, he would say my madhab is Hanafi, or my Madhab is Maliki, or my Madhab is Shafi’ee or my Madhab is Hanbali … and other than this.
And the answer: To say to all of them that we all say: I bear witness that there is nothing worthy og worship except Allah and I bear witness that Muhammad is Allah’s Messenger.
What does the declaration that Muhammad is the Messenger of Allah mean?
The scholars have said: It means: Obidience to him in what he has ordered, staying away from what he has forbidden, believing what he has given news of and not to worship Allah except by the way he worshipped Allah. This is the meaning of Muhammad is the Messenger of Allah.
So if one says my Madhab is so and so or my Madhab is so and so we say to him: this is the statement of the Messenger of Allah (Salallahu alaihi wa sallam), therefore we do not oppose his statement for the statement of anyone else. Even the Imams have prevented people from following every single one of their statements, And they all have said: whenever the truth has been clarified it is compulsory to return to it.
We therefore say to that brother who has opposed us by saying that he follows Madhab so and so: Ourselves and you declare that Muhammad (Salallahu alaihi wa sallam) is the Messenger of Allah. And this declaration means that we should not follow anyone except the Messenger of Allah (Salallahu alaihi wa sallam).