what is known. Allah knows that whoever is able to perform Hajj, stand in prayer, and fast possesses that ability, and He knows that this person is able and performs what he is able to do. What is known, then, is that the act does not occur because the servant does not will it, not because he is unable to perform it—just as with things within his power which he knows he will not do because he does not will them, not because he lacks the power to do them. The servant is able to act, although Allah knows that he will not act despite having that ability. This is why He punishes him: He has commanded him only to do what he is able to do, not what he is unable to do. Whoever lacks the ability, He neither commands him nor punishes him for what he cannot do.

If it is said:

“It follows that he must be able to change Allah’s knowledge, because Allah knows that he will not act. Thus, if he is able to act, he is able to change Allah’s knowledge.”

The answer is:

“This is a fallacy. Merely having the ability to act does not entail any change in that knowledge. Those who imagine such a change imagine it only if the act occurs. But if the act were to occur, what was known would have been its occurrence, not its nonoccurrence. It is therefore impossible for the act to occur while Allah knows that it will not occur. Rather, if it occurs, Allah already knew that it would occur; and if it does not occur, Allah already knew that it would not occur. We know what Allah knows only through what becomes manifest, and Allah’s knowledge corresponds to reality. Thus, nothing can occur that would entail a change in His knowledge. Rather, whatever occurs is precisely what was known. The servant who has not acted has done nothing that changes that knowledge; rather, he is able to do what has not occurred