it, too, and it frightens him, but he can do nothing except stare at his hands. He looks at them as though he had never seen them before, and he feels that looking at them is like getting his eyes gouged out. It is the blood on his hands that causes this horrible fascination, and he feels that the blood can never be washed away. Before his hands are clean, they will make all the seas of the world turn red: "Will all great Neptune's ocean wash this blood / Clean from my hand? No, this my hand will rather / The multitudinous seas incarnadine, / Making the green one red" (2.2.57-60). As she returns, Lady Macbeth hears what Macbeth is saying to himself, and she comments, "My hands are of your colour; but I shame / To wear a heart so white" (2.2.61-62). She means that her hands are red, too (because she has been busy smearing the King's blood on the grooms), but that she would be ashamed to have a heart as white as Macbeth's. A white heart is white because it has no blood, and the person with a white heart is a coward. As she delivers this insult, we hear the knocking again, and Lady Macbeth takes her husband away so that they can wash up. In her opinion, it will only take a little water to make them innocent. She also tells him he must put on his night-gown, so that if they have to get up and talk to whoever is knocking, it won't look like they've been up all night. He's unresponsive, and seems lost in his thoughts. She advises him to snap out of it, but he can't. As he is being led away, he says that "To know my deed, 'twere best not know myself" (2.2.70). He means that if he fully understands what he has done, he will see what a monster he has become, and he doesn't want to know that monster. At the very last, as we hear the knocking again, Macbeth wishes none of it had ever happened, and he calls out "Wake Duncan with thy knocking! I would thou couldst!" (2.2.71). Summary of Act 2, Scene 3: The Porter pretends that he is hell's gatekeepe...
