obligatory elements whose omission leaves it short of obligatory completeness while it remains valid, according to the schools of Abū Hanīfah, Ahmad, and Mālik. Some omissions within prayer can be remedied by the prostration of forgetfulness, while others cannot.

You have thus seen that the parts of a thing differ in their rulings, both under religious law and in the natural order. If an objector says, “This part belongs to its essence, while that part lies outside its essence,” he is asked, “What do you mean by ‘essence’?” If he says, “I mean that whose loss renders its possessor a disbeliever,” he is told: “In this respect, faith does not have a single essence—like the essence of what the term ‘Muslim’ denotes—for all legally accountable people at all times, as is the case with blackness and whiteness. Rather, faith and disbelief vary according to the accountable individual, whether the obligation has been communicated to him, whether the injunction imposing that obligation has ceased to apply, and so forth.”

Likewise, faith and what is obligatory for another person, considered without qualification, are not the same as the faith obligatory for him at every particular time. When Allah sent Muhammad as a messenger to creation, people were obliged to believe what he reported and obey what he commanded. At that time, he had not commanded them to perform the five daily prayers, fast the month of Ramadan, or make the pilgrimage to the House. Nor had he forbidden them wine, usury, and similar things, and most of the Quran had not yet been revealed. Whoever then believed him concerning what had been revealed of the Quran and acknowledged what he had commanded of the two testimonies of faith and their attendant requirements was, at that time, a believer whose faith was complete in all that was required of him. Yet, had he come with that same faith after the Hijrah, it would not have been accepted from him; had he confined himself to it, he would have been a disbeliever.

Imam Ahmad said: “Faith was incomplete at the outset, then continued to increase until it became complete.” For this reason,