One literary device Malamud uses in "The Magic Barrel" is symbolism:
Although it was still February, winter was on its last legs, signs of which he had for the first time in years begun to notice. He now observed the round white moon, moving high in the sky through a cloud menagerie, and watched with half-open mouth as it penetrated a huge hen, and dropped out of her like an egg laying itself.
The moon is symbolized as an egg dropping out of a hen-shaped cloud. This passage has two other literary devices as well: personification ("winter is on its last legs") and metaphor ("cloud menagerie").
Another device he uses is imagery: "Leo saw a profusion of loaves of bread go flying like ducks high over his head, not unlike the winged loaves by which he had counted himself to sleep last night." "Flying like ducks" is a simile.
More imagery appears when Leo meets his intended bride: "From afar he saw that her eyes—clearly her father’s—were filled with desperate innocence. He pictured, in her, his own redemption. Violins and lit candles revolved in the sky. Leo ran forward with flowers outthrust."
The last sentence is an example of irony: "Around the corner, Salzman, leaning against a wall, chanted prayers for the dead." Leo is beginning a new phase of life, but Salzman reacts as if it is his funeral.
I hope this helps!