This is one of the portents of Prophethood and a clear proof of it. Before the Prophet’s commissioning—and afterward as well—the hurling of fiery missiles was slight; the sky was never saturated with them as it became during the descent of the Qur’an.

The Exalted said:

“Shall I tell you upon whom the devils descend? They descend upon every habitual liar, every hardened sinner. They eavesdrop, and most of them are liars.” (al-Shuʿarāʾ 26:221-223)

The term al-affāk denotes a persistent liar, while al-athīm refers to a depraved evildoer, just as He also said:

“We shall seize him by the forelock—a lying, sinful forelock.” (al-ʿAlaq 96:15-16)