Jamieson, Fausset and Brown on John 20:11-15

11-15. But Mary stood without at the sepulchre weeping, &c.--Brief was the stay of those two men. But Mary, arriving perhaps by another direction after they left, lingers at the spot, weeping for her missing Lord. As she gazes through her tears on the open tomb, she also ventures to stoop down and look into it, when lo! "two angels in white" (as from the world of light, and see on Mt 28:3) appear to her in a "sitting" posture, "as having finished some business, and awaiting some one to impart tidings to" [Bengel].