When his men were overpowered by Muawiya''s men
Nahj al-Balāgha|Volume 1|Book 1|Chapter 25
اللَّهُمَّ إِنِّي قَدْ مَلِلْتُهُمْ وَمَلُّوني، وَسَئِمْتُهُمْ وَسَئِمُوني، فَأَبْدِلنِي بِهِمْ خَيْراً مِنْهُمْ، وأَبْدِلُهمْ بِي شَرَّاً مِنِّى، اللَّهُمَّ مِثْ قُلُوبَهُمْ كَمَا يُمَاثُ الْمِلْحُ فِي الْمَاءِ،
O my Allāh they are disgusted of me and I am disgusted of them. They are weary of me and I am weary of them. Change them for me with better ones and change me for them with worse one. O my Allāh melt their hearts as salt melts in water.