the people to go out on (1) military expeditions, nor would he designate by name the particular individuals who were to go. Rather, he would call upon them, and whoever chose to take part in the campaign would go forth. This is why those who went forth were favored (2) over those who stayed behind. Had going forth been individually mandated, each of them would merely have been obeying his command.

Indeed, Allah Most High says:

“Those believers who stay behind—except those with disabilities—are not equal to those who strive in Allah’s cause with their wealth and their lives. Allah has favored those who strive with their wealth and their lives over those who stay behind by one degree. To each Allah has promised the best reward, but Allah has favored those who strive over those who stay behind with a tremendous reward—ranks from Him, forgiveness, and mercy. And Allah is Ever-Forgiving, Most Merciful.”

[Surah al-Nisāʾ: 95–96]

Usāma—may Allah be pleased with him—was one of the commanders of the military detachments, and the commanders of such detachments were not called caliphs. They neither succeeded the Messenger of Allah—peace and blessings be upon him—after his death nor acted as his deputies during his absence in any matter that he had personally administered. Rather, he initiated a journey and mission for them and appointed one of them over it (3). Thus, that man assumed charge of it (4) from the outset, not as the successor of someone who had performed it before him. Administrative authority over cities and villages may be called a succession, while the administrative jurisdiction itself may be called a mikhlāf (province). These are verbal designations (5), applied according to language and usage.

And as for his statement (6), “He died without dismissing him.”