Surah Al-Hashr 59:14

لَا يُقَـٰتِلُونَكُمْ جَمِيعًا إِلَّا فِى قُرًى مُّحَصَّنَةٍ أَوْ مِن وَرَآءِ جُدُرٍۭ ۚ بَأْسُهُم بَيْنَهُمْ شَدِيدٌ ۚ تَحْسَبُهُمْ جَمِيعًا وَقُلُوبُهُمْ شَتَّىٰ ۚ ذَٰلِكَ بِأَنَّهُمْ قَوْمٌ لَّا يَعْقِلُونَ

They will not fight you all except within fortified cities or from behind walls. Their violence [i.e., enmity] among themselves is severe. You think they are together, but their hearts are diverse. That is because they are a people who do not reason.

Translation: Saheeh International

Tafsir

They that is the Jews will not fight against you together all in a single body except in fortified towns or from behind some wall jidār a variant reading has plural judur ‘walls’ some kind of protective fence. Their might their belligerence is great among themselves. …

Excerpt from Tafsir al-Jalalayn, commentary on 59:14, via Quran.com. The reader has the full commentary and 9 more tafsirs.