The Messenger of Allah (may peace he upon him) used to touch our shoulders in prayer and say: Keep straight, don't be irregular, for there would be dissension in your hearts. Let those of you who are sedate and prudent be near me, then those who are next to them, then those who are next to them. Abu Mas'ud said: Now-a-days there is much dissension amongst you. (Using translation from Muslim 432a)  

كَانَ رَسُولُ اللهِ ﷺ يَمْسَحُ مَنَاكِبَنَا فِي الصَّلَاةِ وَيَقُولُ «لَا تَخْتَلِفُوا فَتَخْتَلِفَ قُلُوبُكُمْ لِيَلِنِي مِنْكُمْ أُولُو الْأَحْلَامِ وَالنُّهَى ثُمَّ الَّذِينَ يَلُونَهُمْ ثُمَّ الَّذِينَ يَلُونَهُمْ» قَالَ أَبُو مَسْعُودٍ فَأَنْتُمُ الْيَوْمَ أَشَدُّ اخْتِلَافًا  

"While I was in the Masjid in the first row, a man pulled me from behind and moved me aside, and took my place. By Allah, I could not focus on my prayer, then when he left I saw that it was Ubayy bin Ka'b. He said: '0 boy, may Allah protect you from harm. This is what the Prophet instructed us to do, to stand directly behind him.' Then he (Ubayy) turned to face the Qiblah and said: 'Doomed are Ah1 Al-'Uqd, by the Lord of the Ka'bah! - three times.'Then he said: 'By Allah, I am not sad for them, but I am sad for the people whom they have misled.' I said: '0 Abu Ya'qub, what do you mean by Ah1 Al-'Uqd?' He said: 'The rulers."' (Using translation from Nasāʾī 808)  

يَا فَتَى لَا يَسُوءُكَ اللهُ إِنَّ هَذَا عَهْدٌ مِنَ النَّبِيِّ ﷺ إِلَيْنَا أَنْ نَلِيَهُ ثُمَّ اسْتَقْبَلَ الْقِبْلَةَ فَقَالَ «هَلَكَ أَهْلُ الْعَقْدِ وَرَبِّ الْكَعْبَةِ ثَلَاثًا» ثُمَّ قَالَ «وَاللهِ مَا عَلَيْهِمْ آسَى وَلَكِنْ آسَى عَلَى مَنْ أَضَلُّوا» قُلْتُ يَا أَبَا يَعْقُوبٍ مَا يَعْنِي بِهِ أَهْلَ الْعَقْدِ؟ قَالَ «الْأُمَرَاءُ»