Surah 4. An-Nisaa', Ayah 95

Lit., "who sit [at home]" - i.e., who do not participate in the struggle in God's cause, be it physical or moral.

The term mujahid is derived from the verb jahada, which means "he struggled" or "strove hard" or "exerted himself", namely, in a good cause and against evil. Consequently, jihad denotes "striving in the cause of God" in the widest sense of this expression: that is to say, it applies not merely to physical warfare (qital) but to any righteous struggle in the moral sense as well; thus, for instance, the Prophet described man's struggle against his own passions and weaknesses (jihad an-nafs) as the "greatest jihad" (Bayhaqi, on the authority of Jabir ibn 'Abd Allah).

 This includes women, the elderly, the sick, etc.

Allah's goodness is promised to all people of Faith. But there are degrees among men and women of Faith. There are people with natural inertia: they do the minimum that is required of them, but no more. There are people who are weak in will: they are easily frightened. There are people who are so strong in will and so firm in faith that they are determined to conquer every obstacle, whether in their own physical or other infirmities or in the external world around them. In a time of jihad, when people give their all, and even their lives, for the common cause, they must be accounted more glorious than those who sit at home, even though they have good will to the cause and carry out minor duties in aid. The special reward of such self-sacrifice is special forgiveness and mercy, as proceeding from the direct approbation and love of Allah.