If someone were to ask: The grave is confined and narrow, so how can a person sit up?
The answer is: First, in matters of the unseen, the believer is obliged to accept and affirm; he should not ask about what lies beyond that. Rather, he says: “We hear, believe, affirm, and accept.” He should not ask, “How?” or “Why?” For only one who doubts asks how and why. As for the one who believes and whose heart is reassured by the reports of Allah and His Messenger, he submits and says: “Allah knows best how this occurs.”
Second, the states of the Hereafter cannot be measured by the states of this world, because of the immense difference between them and the absence of any common basis that would warrant comparing one to the other. The soul’s connection to the body after death is not like its connection to it during life. Indeed, even the soul’s connection to the body during sleep is unlike its connection to it while awake. The soul has momentous states in relation to the body that a human being cannot comprehend, and its connection to the body after death cannot be compared to its connection to it during life.
Consider a person in his sleep: he sees himself going and returning, travelling, speaking with people, and meeting people who are alive and dead. He may see that he has a beautiful garden or a desolate, dark house. He may see himself riding in a comfortable car; at one time he sees himself crashing into something, and at another, being struck by something. All of this is possible, even though the person remains upon his bed unchanged—even the covering over him has not changed. This is a real occurrence when the dream is a righteous one.
Thus, a person may be made to sit up in his grave and be questioned, even if the grave is confined and narrow.
The trial, then, is real: a person is questioned about three matters—his Lord, his religion, and his Prophet. We have already mentioned how the one being questioned responds, and that