فَتَقَطَّعُوٓاْ أَمۡرَهُم بَيۡنَهُمۡ زُبُرٗاۖ كُلُّ حِزۡبِۭ بِمَا لَدَيۡهِمۡ فَرِحُونَ ٥٣
But they [i.e., the people] divided their religion among them into portions [i.e., sects] - each faction, in what it has,1 rejoicing.
Translation: Saheeh International (English)
1 Of beliefs, opinions, customs, etc.
Each word's meaning and sound
After they passed away, their followers were divided in religion and became sects and groups, with each group conceited in believing that whatever it believed in was the true acceptable religion according to Allah, disregarding the views of anyone else.
Al-Mukhtasar in interpreting the Noble Quran