Quran 9:102—and when Allah says “perhaps,” it is a certainty.
When this verse was revealed, the Prophet ﷺ sent for them, released them, and accepted their excuse. Then, after they offered their wealth, the verse was sent down: “Take from their wealth a charity by which you purify them and cause them to grow thereby” (Quran 9:103). A similar report is transmitted by ʿAṭiyyah al-ʿAwfī from Ibn ʿAbbās.
ʿUqayl narrated from Ibn Shihab, from ʿAbd al-Raḥmān ibn ʿAbd Allāh ibn Kaʿb ibn Mālik, who said his father related: I heard Kaʿb recount his story of staying behind from the Messenger of Allah ﷺ on the Expedition of Tabuk.
Kaʿb said: I never stayed behind from any expedition the Messenger of Allah ﷺ undertook except the expedition to Tabuk—though I did miss Badr, yet Allah reproached no one for staying behind from that, for the Messenger of Allah ﷺ had only set out to intercept the Quraysh caravan until Allah brought them and their enemy together without prior arrangement. Indeed, I was present with the Messenger of Allah ﷺ on the Night of the Pledge at al-ʿAqabah, and I would not trade that for having been at Badr, even though Badr is better known among the people.
As for my situation when I remained behind on the Expedition of Tabuk: I had never been stronger nor better supplied than at that time. By Allah, I had never owned two riding animals before, yet for that expedition I possessed both. Whenever the Messenger of Allah ﷺ intended a campaign he would disguise its true objective—until that expedition. It was launched in the fiercest heat, over a long journey through a barren desert against a numerous enemy, so he made the matter clear to the Muslims so they could equip themselves fully and informed them of the direction he meant to take. Those accompanying the Messenger of Allah ﷺ were so many that no written register could encompass them.
Kaʿb continued: Thus anyone who wished to stay behind imagined he could conceal it, since no revelation had yet been sent about him. The Messenger of Allah ﷺ set out on that campaign when fruit was ripe and shade was most inviting, and my inclination was toward them. So he departed, and the Muslims went out with him.