Al-Bukhari recorded that Al-Bara' said, "When the Ayah,
لاَّ يَسْتَوِى الْقَـعِدُونَ مِنَ الْمُؤْمِنِينَ
(Not equal are those of the believers who sit (at home),) was revealed, the Messenger of Allah ﷺ called Zayd and commanded him to write it. Then, Ibn Umm Maktum came and mentioned that he was blind. Allah revealed,
غَيْرُ أُوْلِى الضَّرَرِ
(except those who are disabled (by injury or are blind or lame))." Al-Bukhari recorded that Sahl bin Sa`d As-Sa`di said, "I saw Marwan bin Al-Hakam sitting in the Masjid. I came and sat by his side. He told us that Zayd bin Thabit told him that Allah's Messenger ﷺ dictated this Ayah to him,
لاَّ يَسْتَوِى الْقَـعِدُونَ مِنَ الْمُؤْمِنِينَ غَيْرُ أُوْلِى الضَّرَرِ وَالْمُجَـهِدُونَ فِى سَبِيلِ اللَّهِ
(Not equal are those of the believers who sit (at home), except those who are disabled, and those who strive hard and fight in the cause of Allah) Ibn Umm Maktum came to the Prophet as he was dictating that very Ayah to me. Ibn Umm Maktum said, `O Allah's Messenger! By Allah, if I had power, I would surely take part in Jihad.' He was a blind man. So Allah sent down revelation to His Messenger while his thigh was on mine and it became so heavy for me that I feared that my thigh would be broken. That ended after Allah revealed,
غَيْرُ أُوْلِى الضَّرَرِ
(except those who are disabled)." This was recorded by Al-Bukhari. At-Tirmidhi recorded that Ibn `Abbas said,
لاَّ يَسْتَوِى الْقَـعِدُونَ مِنَ الْمُؤْمِنِينَ غَيْرُ أُوْلِى الضَّرَرِ
(Not equal are those of the believers who sit (at home), except those who are disabled), refers to those who did not go to the battle of Badr and those who went to Badr. When the battle of Badr was about to occur, Abu Ahmad bin Jahsh and Ibn Umm Maktum said, `We are blind, O Messenger of Allah! Do we have an excuse' The Ayah,
لاَّ يَسْتَوِى الْقَـعِدُونَ مِنَ الْمُؤْمِنِينَ غَيْرُ أُوْلِى الضَّرَرِ
(Not equal are those of the believers who sit (at home), except those who are disabled) was revealed. Allah made those who fight, above those who sit in their homes not hindered by disability.
وَفَضَّلَ اللَّهُ الْمُجَـهِدِينَ عَلَى الْقَـعِدِينَ أَجْراً عَظِيماًدَرَجَـتٍ مِّنْهُ
(but Allah has preferred those who strive hard and fight, above those who sit (at home), by a huge reward. Degrees of (higher) grades from Him), above the believers who sit at home without a disability hindering them." This is the wording recorded by At-Tirmidhi, who said, "Hasan Gharib. Allah's statement,
لاَّ يَسْتَوِى الْقَـعِدُونَ مِنَ الْمُؤْمِنِينَ
(Not equal are those of the believers who sit (at home),) this is general. Soon after, the revelation came down with,
غَيْرُ أُوْلِى الضَّرَرِ
(except those who are disabled). So whoever has a disability, such as blindness, a limp, or an illness that prevents them from joining Jihad, they were not compared to the Mujahidin who strive in Allah's cause with their selves and wealth, as those who are not disabled and did not join the Jihad were. In his Sahih, Al-Bukhari recorded that Anas said that the Messenger of Allah ﷺ said,
«إِنَّ بِالْمَدِينَةِ أَقْوَامًا مَا سِرْتُمْ مِنْ مَسِيرٍ، وَلَا قَطَعْتُمْ مِنْ وَادٍ، إِلَّا وَهُمْ مَعَكُمْ فِيه»
قالوا: وهم بالمدينة يا رسول الله؟ (There are people who remained in Al-Madinah, who were with you in every march you marched and every valley you crossed.) They said, "While they are still in Al-Madinah, O Messenger of Allah" He said,
«نَعَمْ حَبَسَهُمُ الْعُذْر»
(Yes. Only their disability hindered them (from joining you).) Allah said,
وَكُلاًّ وَعَدَ اللَّهُ الْحُسْنَى
(Unto each, Allah has promised good) meaning, Paradise and tremendous rewards. This Ayah indicates that Jihad is not Fard on each and every individual, but it is Fard Kifayah (which is a collective duty). Allah then said,
وَفَضَّلَ اللَّهُ الْمُجَـهِدِينَ عَلَى الْقَـعِدِينَ أَجْراً عَظِيماً
(but Allah has preferred those who strive hard and fight, above those who sit (at home), by a huge reward). Allah mentions what He has given them rooms in Paradise, along with His forgiveness and the descent of mercy and blessing on them, as a favor and honor from Him. So He said;
دَرَجَـتٍ مِّنْهُ وَمَغْفِرَةً وَرَحْمَةً وَكَانَ اللَّهُ غَفُوراً رَّحِيماً
(Degrees of (higher) grades from Him, and forgiveness and mercy. And Allah is Ever Oft-Forgiving, Most Merciful.). In the Two Sahihs, it is recorded that Abu Sa`id Al-Khudri said that the Messenger of Allah ﷺ said,
«إِنَّ فِي الْجَنَّةِ مِائَةَ دَرَجَةٍ، أَعَدَّهَا اللهُ لِلْمُجَاهِدِينَ فِي سَبِيلِهِ، مَا بَيْنَ كُلِّ دَرَجَتَيْنِ كَمَا بَيْنَ السَّمَاءِ وَالْأَرْض»
(There are a hundred grades in Paradise that Allah has prepared for the Mujahidin in His cause, between each two grades is the distance between heaven and Earth.)