The Quran

Preface

لا يُقاتِلونَكُم جَميعًا إِلّا في قُرًى مُحَصَّنَةٍ أَو مِن وَراءِ جُدُرٍ ۚ بَأسُهُم بَينَهُم شَديدٌ ۚ تَحسَبُهُم جَميعًا وَقُلوبُهُم شَتّىٰ ۚ ذٰلِكَ بِأَنَّهُم قَومٌ لا يَعقِلونَ

Yusuf Ali

They will not fight you (even) together, except in fortified townships, or from behind walls.¹ Strong is their fighting (spirit) amongst themselves: thou wouldst think they were united, but their hearts are divided:² that is because they are a people devoid of wisdom.

They have not sufficient self-confidence or elan to sustain them in a fight except under material advantages or defences. Even if they join forces, they have not sufficient trust in each other to expose themselves to open fighting.
'It may be that they have a strong fighting spirit among themselves, but they have no Cause to fight for and no common objective to achieve. The Meccan Pagans want to keep their own unjust autocracy; the Medīna Hypocrites wish for their own domination in Medīna; and the Jews want their racial superiority established over the Arabs, of whose growing union and power they are jealous.' Their pretended alliance could not stand the strain of either a defeat or a victory. If they had been wise, they would have accepted the Cause of Unity, Faith, and Truth.