9:120
مَا كَانَ لِ أَهْلِ ٱلْ مَدِينَةِ وَ مَنْ حَوْلَ هُم مِّنَ ٱلْ أَعْرَابِ أَن يَتَخَلَّفُ وا۟ عَن رَّسُولِ ٱللَّهِ وَ لَا يَرْغَبُ وا۟ بِ أَنفُسِ هِمْ عَن نَّفْسِ هِۦ ذَٰلِكَ بِ أَنَّ هُمْ لَا يُصِيبُ هُمْ ظَمَأٌ وَ لَا نَصَبٌ وَ لَا مَخْمَصَةٌ فِى سَبِيلِ ٱللَّهِ وَ لَا يَطَـُٔ ونَ مَوْطِئًا يَغِيظُ ٱلْ كُفَّارَ وَ لَا يَنَالُ ونَ مِنْ عَدُوٍّ نَّيْلًا إِلَّا كُتِبَ لَ هُم بِ هِۦ عَمَلٌ صَٰلِحٌ إِنَّ ٱللَّهَ لَا يُضِيعُ أَجْرَ ٱلْ مُحْسِنِينَ
It was not [proper] for the people of Madinah and those surrounding them of the bedouins that they remain behind after [the departure of] the Messenger of Allah or that they prefer themselves over his self. That is because they are not afflicted by thirst or fatigue or hunger in the cause of Allah, nor do they tread on any ground that enrages the disbelievers, nor do they inflict upon an enemy any infliction but that is registered for them as a righteous deed. Indeed, Allah does not allow to be lost the reward of the doers of good.