Macbeth: Blood Will Have Blood In Shakespeare's tragedy Macbeth, Macbeth says, "Blood will have blood…," is implying one of the main themes. Along with this quotation, there are many more quotations throughout the story that support the theme of blood. Macbeth has always been known to be a bloody story, but it is proven so much by the numerous quotations dealing with blood and murder. The first well know quotation to come across, dealing with blood, would most likely be agreed upon to be "Will all great Neptune's oceans wash this blood clean from my hand?" (2.2.78-79) Macbeth s