Sayyiduna ‘Abdullah ibn ‘Umar (radiyallahu ‘anhuma) reports that Nabi (Sallallahu ‘alayhi wa sallam) said: “Allah Ta’ala will never allow my Ummah to unite upon misguidance, Allah Ta’ala’s assistance is with the group and whomsoever deviates from the group will be cast into the fire”.
(Sunan Tirmidhi, hadith: 2167)
The above hadith has been reported via several other chains, and parts of the above narration are also supported by various authentic hadiths recorded in Sahih Bukhari and Sahih Muslim which have a similar meaning as the hadith in question. It is therefore declared as reliable.
(See Sunan ibn Majah and Misbahus Zujajah, hadith: 3950, Al Mu’jamul Kabir, hadith: 13623, Majma’uz Zawaid vol. 5 pg. 218, Mustadrak Hakim, vol. 1 pg. 115 and Al Maqasidul Hasanah, hadith: 1288. Sahih Bukhari, hadith: 1367 and Sahih Muslim, hadith: 949)