بسم الله الرحمن الرحيم
Q. Oh Noble Shaykh is going out for the period of months or weeks or days as the Tableeghis do, Sunnah or Bid'ah? Also is it permissible to go out with this group if the person is learned with the legislative knowledge?
A. This is not permissible. This is Bid'ah (Innovation). Going out for forty days or four months or four days, this is Bid'ah and this group is a Soofee group. It is established that this group is a Soofee group, Deobandiyyah. They infiltrated our land and other lands for the purpose of spreading Sufism. It is not permissible for the person of the Sunnah and the person of Tawheed to go out with them. That's because if he goes out with them, he would have aided them in the spreading of innovation. Also the people will use him as a proof (to go out with the Tableeghis). They will say: So and so went out with them! Or they will say: Such and Such people went out with them! Or the people of the land. Therefore it is obligatory for the person to reject these individuals, it is obligatory that the people reject these individuals and they're not to be turned to in order that they return back to their lands with their innovation and not spread it amongst us. The person should not say: I'm going to go out with them in order to teach them. Keep this type of thinking far from your mind. They do not accept the teachings. That is because they are people who have a foundation (of innovation) with them and a methodology. They came to teach you and they didn't come for you you to teach them!! They came to teach you their Sufism and their methodology. They didn't come to learn from you. If they wanted to learn they would have sat at the hands of the Scholars in the Masaajid and read the Books (of the Sunnah). It is not permissible to be deceived by these mistakes."
Taken from: "Al-Ijaabat al-Muhimmah" Part 1 p.g. 102-103
Translated By: Abu Yusuf Khaleefah
Source: http://31097.multiply.com/journal/item/81