When his men were overpowered by Muawiya''s men
Nahj al-Balāgha|Volume 1|Book 1|Chapter 25
أَمَاوَاللهِ لَوَدِدْتُ أَنَّ لِي بِكُمْ أَلفَ فَارِس مِنْ بَنِي فِرَاسِ بْنِ غَنْم : هُنَالِكَ، لَوْ دَعَوْتَ، أَتَاكَ مِنْهُمْ فَوَارِسُ مِثْلُ أَرْمِيَةِ الحَمِيم
By Allāh I wish I had only a thousand horsemen of Banu Firās ibn Ghanm (as the poet says) : If you call them the horsemen would come to you like the summer cloud.