Usurpation of the caliphate from him
Nahj al-Balāgha|Volume 1|Book 1|Chapter 162
وَهَلُمَّ الْخَطْبَ فِي ابْنِ أَبِي سُفْيَانَ، فَلَقَدْ أَضْحَكَنِي الدَّهْرُ بَعْدَ إبْكَائِهِ، وَلاَ غَرْوَوَاللهِ، فَيَا لَهُ خَطْباً يَسْتَفْرِغُ الْعَجَبَ، وَيُكْثِرُ الاَوَدَ، حَاوَلَ الْقَوْمُ إِطْفَاءَ نَورِ اللهِ مِنْ مِصْباحِهِ، وَسَدَّ فَوَّارِهِ مِنْ يَنْبُوعِهِ، وَجَدَحُوا بَيْنِي وَبَيْنَهُمْ شِرْباً وَبِيئاً، فَإنْ تَرْتَفِعْ عَنَّا وَعَنْهُمْ مِحَنُ الْبَلْوَى، أَحْمِلْهُمْ مِنَ الْحَقِّ عَلَى مَحْضِهِ، وَإنْ تَكُنِ الاُخْرَى، ﴿فَلَا تَذْهَبْ نَفْسُكَ عَلَيْهِمْ حَسَرَاتٍ إِنَّ اللهَ عَلِيمٌ بِمَا يَصْنَعُونَ﴾.
Come and look at the son of Abū Sufyān (Mu‘āwiyah). Time has made me laugh after weeping. No wonder, by Allāh; what is this affair which surpasses all wonder and which has increased wrongfulness. These people have tried to put out the flame of Allāh’s light from His lamp and to close His fountain from its source. They mixed epidemicproducing water between me and themselves. If the trying hardships were removed from among us, I would take them on the course of truthfulness other wise: “... So let not thy self go (in vain) in grief for them; verily Allāh knoweth all that they do.” (Qur’ān, 35:8)