At-Tawbah 9:120

مَا كَانَ لِأَهۡلِ ٱلۡمَدِينَةِ وَمَنۡ حَوۡلَهُم مِّنَ ٱلۡأَعۡرَابِ أَن يَتَخَلَّفُواْ عَن رَّسُولِ ٱللَّهِ وَلَا يَرۡغَبُواْ بِأَنفُسِهِمۡ عَن نَّفۡسِهِۦۚ ذَٰلِكَ بِأَنَّهُمۡ لَا يُصِيبُهُمۡ ظَمَأٞ وَلَا نَصَبٞ وَلَا مَخۡمَصَةٞ فِي سَبِيلِ ٱللَّهِ وَلَا يَطَـُٔونَ مَوۡطِئٗا يَغِيظُ ٱلۡكُفَّارَ وَلَا يَنَالُونَ مِنۡ عَدُوّٖ نَّيۡلًا إِلَّا كُتِبَ لَهُم بِهِۦ عَمَلٞ صَٰلِحٌۚ إِنَّ ٱللَّهَ لَا يُضِيعُ أَجۡرَ ٱلۡمُحۡسِنِينَ 120

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