Surah 48. Al-Fath, Ayah 17

This latter applies, by obvious implication, to such as are unable to participate in the fighting physically, but are in their hearts with those who fight.

These three categories circumscribe metonymically all kinds of infirmities or disabilities which may prevent a person from actively participating in a war in God's cause.

There may be neither fighting nor booty. But all who obey the call to Jihad with perfect discipline will get the Rewards of the Hereafter. The blind, the maimed, and the infirm will of course be exempted from active compliance with the Call, but they can render such services as are within their power, and then they will not he excluded from the reward.