The Prophet of Allah, sallallaahu ‘alayhi wa sallam, facilitated things for them and alleviated their hardship
Zayd ibn Thaabit (a Companion) narrated that the Messenger of Allah,sallallaahu ‘alayhi wa sallam, dictated the following verse (which means):
«Not equal are those believers remaining (at home) and the Mujahideen, [who strive and fight] in the cause of Allah with their wealth and their lives.»
Zayd said: “Then, Ibn Umm Maktoom approached while the Prophet of Allah, sallallaahu ‘alayhi wa sallam, was dictating those words to me and said: ‘O Messenger of Allah, if I was able to go on Jihaad (fighting for the cause of Allah), I would have gone to fight,’ and he was a blind man.” Zayd continued, “So Allah revealed verses to His Messenger, sallallaahu ‘alayhi wa sallam, while his thigh was on my thigh. He, sallallaahu ‘alayhi wa sallam, started receiving revelation, and his thigh became so heavy that I feared it would crush my thigh, then his state was lifted, and Allah sent (what means):
«…other than the disabled...»”
In order to make things easier for those who have special needs,
(what means): «There is not upon the blind any guilt or upon the lame any guilt or upon the ill any guilt [for remaining behind]. And whoever obeys Allah and His Messenger, He will admit him to gardens beneath which rivers flow; but whoever turns away, He will punish him with a painful punishment.»
Thus, Allah lifted the obligation to fight Jihaad in the battlefield off them, and did not command them to carry weapons or to go out with an army in Allah’s Path.