sound health, ample capacity, material means, and the soundness of one’s faculties—this kind of ability exists before the act itself, and the divine address is attached to it, just as the Almighty says, “Allah does not burden any soul beyond its capacity.”

First: an ability on which legal obligation, commands, and prohibitions are based.
Second: an ability by which a person can actually carry out and execute the deed.

Section One – the ability that underlies legal accountability: it is capacity—the person’s scope either to act or to refrain, his potential and readiness. Obligation is linked to this ability. Whoever lacks it is not accountable: the insane and the child are not charged, hence they are neither commanded nor forbidden. When, however, a child reaches seven years of age he possesses a measure of this ability, so he is instructed to perform the prayer for the purposes of recommendation, upbringing, and training in worship. Prayer only becomes obligatory once he reaches puberty, at which point he is legally responsible. This kind of ability, therefore, exists before the act.

Section Two – the ability involved in execution and bringing the deed into existence: this accompanies the act itself. Pilgrimage, for example, requires both kinds of ability. Allah says, “Pilgrimage to the House is a duty owed to Allah by those who are able to find a way to it…” (Āl ʿImrān 97). This is an ability of preparedness: Hajj becomes obligatory upon whoever is capable, and “the way” consists of provisions and a means of transport. When these are available, the pilgrimage is binding, for he has the preparatory ability—an ability that precedes the act. As for the ability that accompanies the act—actually performing the rites of Hajj—a person may lack it, such as one who is chronically ill or extremely old and frail. Such a person lacks the ability to execute the act, though he still possesses an ability