Al-Kashshaf: An-Nur (62)
"The believers are only those who..."
The Almighty intended to show them the gravity of the offense committed by one who leaves the Messenger’s assembly without his permission, "when they are with him upon a matter of collective concern." He made their refraining from leaving until they seek his permission a third pillar alongside faith in Allah and faith in His Messenger. He treated the latter two as a prelude and foundation for the former. This is emphasized by beginning the sentence with innama (exclusively), making "the believers" the subject, and describing them with a relative pronoun whose clause encompasses the mention of both faiths. He then followed this with further confirmation and strictness by restating it in another style: "Those who ask your permission are the ones who believe in Allah and His Messenger."
He included another point: he made the act of seeking permission a verification of the sincerity of both faiths, while alluding to the state of the hypocrites and their slipping away stealthily (liwadhan).
The meaning of "they do not depart until they ask his permission" is: they do not depart until they ask his permission and he grants it to them. Do you not see how he conditioned the matter—even after their request—upon his will and his permission for whomever he deems appropriate?
"A matter of collective concern" (amr jami‘): A matter for which people are gathered. Describing the matter as "collective" is metaphorical, such as fighting an enemy, consulting on an important affair, uniting to intimidate an opponent, or forming an alliance. It may also mean a matter that affects everyone in its harm or benefit. It has also been recited as amr jami‘ (a matter that unites).
In the phrase "when they are with him upon a matter of collective concern," it implies a momentous affair where the Messenger of Allah (ﷺ) requires men of opinion and strength to support and assist him, and to illuminate his path with their insights, knowledge, and experience. For one of them to depart in such a state is burdensome to his heart and disrupts his judgment. Hence, He was strict with them and narrowed the scope regarding permission, even with a valid excuse or pressing personal need, which is what is meant by "for some affair of theirs."
The mention of seeking forgiveness for those who ask permission is evidence that the better and more virtuous path is not to contemplate leaving at all, nor to ask for it.
It is said this was revealed regarding the digging of the Trench, as some people were slipping away without permission. It is also said that this is how people should be with their leaders and those who precede them in religion and knowledge: supporting them, not abandoning them in any crisis, and not dispersing from them. The matter of granting permission is delegated to the leader; he may grant it or withhold it, according to what his judgment dictates.
"Do not make the calling of the Messenger among you like the calling of one of you to another. Allah already knows those who slip away from you stealthily. So let those who dissent from his command beware, lest a trial strike them or a painful punishment strike them."
