Final answer:
Lady Macbeth is the character who says, "All the perfumes of Arabia will not sweeten this little hand," highlighting her deep sense of guilt and the burden of her actions in the play 'Macbeth.'
Step-by-step explanation:
The character from "Macbeth" who laments, "All the perfumes of Arabia will not sweeten this little hand," is Lady Macbeth. This line signifies Lady Macbeth's realization that the guilt from her role in the regicide cannot be washed away by any means. Metaphorically, even the sweetest perfumes of Arabia are insufficient to cleanse her bloodstained conscience. Throughout the play, Lady Macbeth plays a pivotal role, initially acting as the force that propels Macbeth to commit regicide. Her guilt manifests later in the play when she sleepwalks and obsessively attempts to clean her hands of the imaginary bloodstains that symbolize her complicity.