Sahih Muslim #2458 · The Book of Zakat

Sahih MuslimAbu Sa'id al-Khudri reported that the Messenger of Allah
Sahih Muslim · Book 12 · The Book of Zakat
Sahih Muslim · كتاب 12 · كتاب الزكاة
A group would secede itself (from the Ummah) when there would be dissension among the Muslims. Out of the two groups who would be nearer the truth would kill them.
حَدَّثَنَا شَيْبَانُ بْنُ فَرُّوخَ، حَدَّثَنَا الْقَاسِمُ، - وَهُوَ ابْنُ الْفَضْلِ الْحُدَّانِيُّ - حَدَّثَنَا أَبُو نَضْرَةَ، عَنْ أَبِي سَعِيدٍ الْخُدْرِيِّ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏
"‏ تَمْرُقُ مَارِقَةٌ عِنْدَ فُرْقَةٍ مِنَ الْمُسْلِمِينَ يَقْتُلُهَا أَوْلَى الطَّائِفَتَيْنِ بِالْحَقِّ ‏"‏ ‏.‏
Reference : Sahih Muslim 2458In-book reference : Book 12, Hadith 195