and to simplify their manner of performance, as prescribed by Islamic law. This, too, is precisely prescribed when there is a valid excuse, just as it is when there is none.

Thus, someone combining two prayers may not delay a daytime prayer until night or a nighttime prayer until day. The two daytime prayers are Zuhr and Asr, and the two nighttime prayers are Maghrib and Ishā. The same applies to those with valid excuses who reduce the number of units and simplify the manner of performance: this, too, is subject to prescribed times and limits. The actions must have clearly defined beginnings and endings.

Standing is defined by being upright: if someone voluntarily moves from an upright posture into the bent posture of bowing, he has not fulfilled the requirement of standing.

It is well known that the remembrance recited while standing—namely, Quran recitation—is superior to the remembrance recited while bowing and prostrating. Yet the physical acts of bowing and prostrating are superior to the physical act of standing. For this reason, they constitute worship in their own right and, under our religious law, may never be directed to anyone other than Allah. Other evidence has been discussed elsewhere. That being so, it is clear that these actions have prescribed measures and limits according to one’s ability to perform them.

A person prostrating must reach the ground, which is the furthest extent possible; he may not stop short of it except for a valid excuse. He begins the movement of prostration as soon as he starts bending down, whether he prostrates from a standing or a sitting position. The starting point of prostration should therefore be defined accordingly, so that he prostrates from a standing or sitting position, not