In response to a letter from Muawiya
Nahj al-Balāgha|Volume 1|Book 2|Chapter 17
وَأَمَّا اسْتِوَاؤُنَا فِي الْحَرْبِ والرِّجَالِ، فَلَسْتَ بِأَمْضَى عَلَى الشَّكِّ مِنِّي عَلَى الْيَقِينِ، وَلَيْسَ أَهْلُ الشَّامِ بِأَحْرَصَ عَلَى الدُّنْيَا مِنْ أَهْلِ الْعِرَاقِ عَلَى الْآخِرَةِ.
As for our equality in (the art of) war and in (numbers of) men, certainly you cannot be more penetrating in doubtfulness (of belief) than I am in certainty (of belief), and the people of Syria are not more greedy for this world than the people of Iraq are for the next world.