“Come, you spirits / That tend on mortal thoughts, unsex me here, / And fill me from the crown to the toe top-full / Of direst cruelty!” (A4 S1).
refer to the conscience of the pair, but also their concealment towards the others in the play, ridding them of guilt and shame. The reference to the serpent could be a reference to the biblical story of creation and therefore implying that much like Eve, Lady Macbeth has been tempted into the world of evil thus will pay for her transgressions.