The phrase 'غير أولي الضرر' is read with the three vowel markings. The nominative case is an attribute of the 'قاعدين', the accusative case is an exception from them or a state about them, and the genitive case is an attribute of the believers. And 'الضرر' refers to illness or a disability such as blindness, lameness, or similar conditions. And from Zayd ibn Thabit: I was next to the Messenger of Allah, blessings and peace be upon him, when tranquility overcame him. His thigh fell upon my thigh until I feared it would crush me. Then he recovered and said: 'Write.' So I wrote on my shoulder: 'لا يَسْتَوِي الْقاعِدُونَ مِنَ الْمُؤْمِنِينَ غَيْرُ أُولِي الضَّرَرِ وَالْمُجاهِدُونَ.' Then Ibn Umm Maktum, who was blind, said: 'O Messenger of Allah, how about a man who cannot strive among the believers?' Tranquility overcame him again, then he said: 'Recite, O Zayd.' So I recited: 'لا يَسْتَوِي الْقاعِدُونَ مِنَ الْمُؤْمِنِينَ.' He said: 'غير أولي الضرر.' Zayd said: 'Allah revealed it alone, and I added it.' By the One in whose hand is my soul, I can see its addition at a crack in the shoulder. [Narrated by al-Bukhari from the narration of Ibn al-Hakam from Yazid ibn Thabit similarly, and by Abu Dawood, Ahmad, and al-Hakim from the narration of Khārijah ibn Zayd from Zayd ibn Thabit with the mentioned wording.]

And from Ibn Abbas: 'The sitting ones are not equal to those who went out to Badr.' And from Muqatil: 'To Tabuk.' If you say: It is known that the one who sits without excuse and the one who strives are not equal, what is the benefit of negating equality? I say: Its meaning is a reminder of the great disparity and vast difference between them, so that the one who sits may feel ashamed of his low status, and be stirred to strive and desire it and to elevate his rank. And similar to this is: 'هَلْ يَسْتَوِي الَّذِينَ يَعْلَمُونَ وَالَّذِينَ لا يَعْلَمُونَ.' It is intended to motivate the ignorant and his arrogance to fear it [The term 'ليهاب' apparently comes from 'الهوب', which means the blaze of fire, i.e., to ignite it, as in the lexicons.]. So he may rise from the state of ignorance to the honor of knowledge. Allah has favored the strivers, which clarifies what has been negated regarding the equality of the sitting ones and the strivers, as if it were said: Why are they not equal? The response is given. And the meaning is that the sitting ones, except for those who are excused, are not equal, as the statement is an explanation of the first statement that includes this description. And for each group, both the sitting ones and the strivers, Allah has promised the best reward, which is the good reward, namely Paradise, even if the strivers are preferred over the sitting ones in rank.

And from the Prophet, blessings and peace be upon him: 'You have left behind in Medina people whom you did not travel a distance nor cross a valley except that they were with you.' [Narrated by al-Bukhari and Abu Dawood from the narration of Hamid from Anas. And similarly in Muslim from the hadith of Jabir, may Allah be pleased with him.] They are those whose intentions are sound and whose pockets are sincere [The phrase 'ونصحت جيوبهم' in the lexicons means: It is said that he has a good pocket, meaning a good answer. A man with a sincere pocket is one who is trustworthy.]. Their hearts yearn for striving, and they are prevented from traveling due to harm or other reasons. If you say: Allah has mentioned those who are preferred in rank and those who are preferred in degrees, who are they? I say: As for those preferred in one rank, they are those who are preferred over the sitting ones who are excused. And as for those preferred in degrees, they are those who are preferred over the sitting ones who were permitted to remain behind, being sufficient with others, because fighting is a communal obligation. If you say: Why is 'دَرَجَةً' and 'أَجْراً' and 'دَرَجاتٍ' in the accusative case? I say: The accusative of 'دَرَجَةً' is due to its position as a singular instance of preference, as if it were said: He preferred them with one preference. An example of this is your saying: 'ضربه سوطا', meaning he struck him once. And as for 'أَجْراً', it has been made accusative by virtue of preference, because it means: He rewarded them with a reward. And 'دَرَجاتٍ', and 'مغفرة', and 'رحمة' are substitutes for 'أَجْراً'. Or it may be that 'دَرَجاتٍ' is accusative like 'دَرَجَةً', as you say: 'ضربه أسواطا', meaning strikes, as if it were said: And he preferred them with preferences. And 'أَجْراً عَظِيماً' is in the accusative as a state for the indefinite noun which is 'دَرَجاتٍ' that precedes it, and 'مغفرة' and 'رحمة' are in the accusative by implying their actions, meaning: And He forgave them and had mercy on them, forgiveness and mercy.