Those Permitted to Fall Behind in War: Qur’an Verses

لَيْسَ عَلَى الضُّعَفَٓاءِ وَلَا عَلَى الْمَرْضٰى وَلَا عَلَى الَّذ۪ينَ لَا يَجِدُونَ مَا يُنْفِقُونَ حَرَجٌ اِذَا نَصَحُوا لِلّٰهِ وَرَسُولِه۪ۜ مَا عَلَى الْمُحْسِن۪ينَ مِنْ سَب۪يلٍۜ وَاللّٰهُ غَفُورٌ رَح۪يمٌۙ

[But] no blame shall attach to the weak, nor to the sick, nor to those who have no means. [to equip themselves], provided that they are sincere towards Allah and His Apostle: there is no cause to reproach the doers of good, for Allah is much-forgiving, a dispenser of grace.

وَلَا عَلَى الَّذ۪ينَ اِذَا مَٓا اَتَوْكَ لِتَحْمِلَهُمْ قُلْتَ لَٓا اَجِدُ مَٓا اَحْمِلُكُمْ عَلَيْهِۖ تَوَلَّوْا وَاَعْيُنُهُمْ تَف۪يضُ مِنَ الدَّمْعِ حَزَنًا اَلَّا يَجِدُوا مَا يُنْفِقُونَۜ

Nor [shall blame attach] to those who, when they came unto thee [O Prophet, with the request] that thou provide them with mounts, were told by thee, "I cannot find anything whereon to mount you" – [whereupon] they turned away, their eyes overflowing with tears out of sorrow that they had no means to spend [on their equipment].

وَمَا كَانَ الْمُؤْمِنُونَ لِيَنْفِرُوا كَٓافَّةًۜ فَلَوْلَا نَفَرَ مِنْ كُلِّ فِرْقَةٍ مِنْهُمْ طَٓائِفَةٌ لِيَتَفَقَّهُوا فِي الدّ۪ينِ وَلِيُنْذِرُوا قَوْمَهُمْ اِذَا رَجَعُٓوا اِلَيْهِمْ لَعَلَّهُمْ يَحْذَرُونَ۟

With all this, it is not desirable that all of the believers take the field [in time of war]. From within every group in their midst, some shall refrain from going forth to war, and shall devote themselves [instead] to acquiring a deeper knowledge of the Faith. and [thus be able to] teach their home-coming brethren, so that these [too] might guard themselves against evil.