Innovation of Khawarij, showing Bara`at from everyone who went against them even in one issue.
1. Imam Abu Obaid al Qasim ibn Salam narrated from Salamah bin Kuhail said: Zahhaq, Maysarah and Abul Bakhtari agreed that
وَالْبَرَاءَةَ بِدْعَةٌ
al-Bara’at is an innovation. (Kitab al Iman 1/64)
2. Shaykh al Albani commented:
و”البراءة” هي من بدع الخوارج, الذين خرجوا على علي رضي الله عنه وتبرؤوا منه, ثم صارت البراءة لهم مذهباً عرفوا به, حتّى كانوا يتبرؤون ممن كان منهم لمخالفته لهم, ولو في مسألة واحدة. انظر تفسير ذلك في “مقالات الإسلاميين” لأبي الحسين الأشعري 1/156-157.
al-Bara’at is an innovation of Khawarij who did khurooj against Ali May Allah be pleased with him and showed Bara’at from him. Then it became their Madhab, until they started Bara`at from everyone who went against them EVEN (if the other person is going against them) in ONLY ONE ISSUE. See its detail in “Maqalaat al Islamiyeen” by Abul Hasan al Ashari 1/156-157] [Ibid]
3. Islamweb states
The Baraa’ that is dispraised is that which is similar to the way of the Khawaarij, who disassociate themselves from every person who disagrees with them, even in one single issue, even if his disagreement is based on Ijtihaad and misinterpretation of some texts of the Quran and Sunnah. Rather, the one they disagree with might be correct while they are wrong, then they disassociate themselves from him, believing that they are the ones who are correct. So they fit the description in the following verse very well: {Those whose efforts have been wasted in this life while they thought that they were acquiring good by their deeds.} [Quran 18:104] [Islamweb]
4. Ibn Taymiyah said:
“There is no contradiction between one single person receiving mercy and love on one hand and being tortured and hated on the other hand; and that he be rewarded on one hand and punished on the other. The belief of Ahl As-Sunnah wa Al-Jamaa‘ah is that one single person can meet both criteria, contrary to the claim of the Khawaarij and Mu‘tazilah, who claim that a person who deserves punishment from among the Muslims does not come out of Hellfire, so they believe that (some of the) Muslims who worship Allah alone will remain in Hellfire eternally; as they said: whoever deserves punishment does [Islamweb]