(40) باب سُقُوطِ فَرْضِ الْجِهَادِ عَنِ الْمَعْذُورِينَ،
It has been narrated on the authority of Bara' who said:
When the Qur'anic verse:" Those who sit (at home) from among mu'min" (iv. 94) was revealed, the son of Umm Maktum spoke to him (the Holy Prophet). (At this). the words:" other than those who have a trouble (illness)" were revealed.
Reference: Sahih Muslim 1898 b
In-book reference: Book 33, Hadith 207
USC-MSA web (English) reference(deprecated numbering scheme): Book 20, Hadith 4677