It has been narrated on the authority of Abu Ishaq, that he heard Bara' talking about the Qur'anic verse:
Those who sit (at home) from among the believers and those who go out for Jihad in the way of Allah are not aqual (iv. 95). (He said that) the Messenger of Allah ( صلی اللہ علیہ وسلم ) ordered Zaid (to write the verse). He brought a shoulder-blade (of a slaughtered camel) and inscribed it (the verse) thereon. The son of Umm Maktum complained of his blindness to the Prophet ( صلی اللہ علیہ وسلم ). (At this) descended the revelation: Those of the believers who sit (at home) without any trouble (illness, incapacity, disability) (iv. 95). The tradition has been handed down through two other chains of transmitters