"What hands are here! Ha! They pluck out my eyes! Will all great Neptune's ocean wash this blood Clean from my hand ? Act 2, Scene 2, line 57-59
‘Mine eyes are made the fools o’ the other senses, Or else worth all the rest: I see thee still; And on thy blade and dudgeon the gouts of blood, Which was not so before. There’s no such thing’ Act 2, Scene 1, lines 44-47
‘Out damned spot! Out, I say! One; two: why, then, ‘tis time to do’t. Hell is murky! Fie, my lord, fie! A soldier, and afeard? What need we fear who know it, when none can call our power to account? Yet who would have thought the old man to have had so much blood in him?’ Act 5, Scene 1, line 32-37
This scene exhibits powerful imagery. It is portraying that Macbeth is unable to remove the blood from his hands. Neptune's ocean is there to represent Macbeth's guilt. He will always feel this guilt in his consciousness. Right after this quote he says" The multitudinous of the seas incarnadine, making the green one red." This change in colour of the seas represents the everlasting guilt Macbeth will feel.
The thoughts of murdering the king are taking over his mind and causing him to hallucinate. He is visioning a dagger with blood in his hand and its making him weak. The " gouts of blood" are a representation of this guilt and foreshadow these gruesome visions.
In this particular scene, Lady Macbeth is sleepwalking in Macbeth's castle. She knows she guilty and knows the mistakes she has made but she can't "rub the blood off her hands."