In act ii, scene 2, after he murders duncan, macbeth asks, "will all great neptune’s ocean wash this blood / clean from my hand? " neptune was the roman god of the sea. how does this allusion to neptune affect the play? it reveals the great depth of macbeth's guilt, suggesting that all the water in the ocean cannot cleanse him of it. it reveals that macbeth is highly educated, a trait that will serve him well when he assumes the scottish throne. it indicates that macbeth is delusional, imagining blood on his hands where there is none. it suggests that macbeth views duncan as a figure of great power, one whose death he cannot comprehend.