Near the end of “A Prophet,” one of those rare films in which the moral stakes are as insistent and thought through as the aesthetic choices, there’s a scene in which the lead character, Malik, travels to Paris to kill some men. The scene reverberates with almost unbearable tension but is briefly punctured by a seemingly throwaway image: Seconds before he begins shooting, thereby sealing his fate, you see him catch sight of a pair of men’s shoes showcased like jewels in a boutique window in a rich Parisian quarter. He does a double take, a reaction that might mirror that of the anxious viewer who wonders why he doesn’t just get on with it.

Much of what distinguishes “A Prophet” (“Un Prophète”) is revealed in Malik’s brief appreciation of the shoes, as well as the surprise it elicits. He’s window shopping — doesn’t he have some killing to do? Yet these luxury items are resonant, as is their exclusive setting and the way Malik’s admiring gaze momentarily stops the flow of the action: each adds another element to this portrait of an impoverished young Frenchman of Arab descent who is transformed in prison. Over the course of the film Malik will learn to read, to smuggle, to murder, to survive. Which is why when he pauses after unloading his guns, his pale face floating in the sanguineous dark, it looks as if he were emerging from a kind of womb: his metamorphosis is complete.