Authority

Yet he had no authority over them, only that We might distinguish those who believe in the Hereafter from those in doubt.

15:42Lo! as for My slaves, thou hast no power over any of them save such of the froward as follow thee,

34:21And he had no warrant whatsoever against them, save that We would know him who believeth in the Hereafter from him who is in doubt thereof; and thy Lord (O Muhammad) taketh note of all things.