The Prohibition of Division

As Salaam Alaykum Wa Rahmatullahi Wa Barakatuhu

Allah said,


[وَلاَ تَكُونُواْ كَالَّذِينَ تَفَرَّقُواْ وَاخْتَلَفُواْ مِن بَعْدِ مَا جَآءَهُمُ الْبَيِّنَـتُ]

(And be not as those who divided and differed among themselves after the clear proofs had come to them) [3:105].

In this Ayah, Allah forbids this Ummah from imitating the division and discord of the nations that came before them. These nations also abandoned enjoining righteousness and forbidding evil, although they had proof of its necessity.

Imam Ahmad recorded that Abu `Amir `Abdullah bin Luhay said, "We performed Hajj with Mu`awiyah bin Abi Sufyan. When we arrived at Makkah, he stood up after praying Zuhr and said, `The Messenger of Allah said,


«إِنَّ أَهْلَ الْكِتَابَيْنِ افْتَرَقُوا فِي دِينِهِمْ عَلى ثِنْتَيْنِ وَسَبْعِينَ مِلَّةً، وَإِنَّ هذِهِ الْأُمَّةَ سَتَفْتَرِقُ عَلى ثَلَاثٍ وَسَبْعِينَ مِلَّةً يَعْنِي الْأَهْوَاءَ كُلُّهَا فِي النَّارِ إِلَّا وَاحِدَةً وَهِيَ الْجَمَاعَةُ وَإِنَّهُ سَيَخْرُجُ فِي أُمَّتِي أَقْوَامٌ تَجَارَى بِهِمْ تِلْكَ الْأَهْوَاءُ كَمَا يَتَجَارَى الْكَلَبُ بِصَاحِبِه، لَا يَبْقَى مِنْهُ عِرْقٌ وَلَا مَفْصِلٌ إِلَّا دَخَلَه»


(The People of the Two Scriptures divided into seventy-two sects. This Ummah will divide into seventy-three sects, all in the Fire except one, that is, the Jama`ah. Some of my Ummah will be guided by desire, like one who is infected by rabies; no vein or joint will be saved from these desires.)

[Mu`awiyah said next:] By Allah, O Arabs! If you do not adhere to what came to you from your Prophet then other people are even more prone not to adhere to it. '' Similar was recorded by Abu Dawud from Ahmad bin Hanbal and Muhammad bin Yahya.

Source from http://www.tafsir.com/default.asp?sid=3&tid=8974