upon her skinny lips

“I am in blood stepped in so far that should I wade no more,

Returning were as tedious as go o’er.” 

This shows that one death will create another, continuous killing becomes a habit which

heightens the violence and destruction that Macbeth pursues, reveling its ugliness.

This heightens evilness of the witches, as the have a sailors thumb. Wreck'd as homeward he did come, this may mean he did not actually come home.

This develops the theme of violence and disorder, where Macbeth abandons his morals and commits himself to more murder... from this point, there is less guilt and fear in his dialogue.

This quote from Macbeth displays his inner turmoil and that his thoughts are conflicted.

“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”
(2.2.59-61).

The imagery
of the vastness of the earth’s clean oceans being washed blood-red by the merciless
deed of regicide powerfully cements the gravity of the deed that Macbeth has
committed.

fly to the court of England and unfold

his message ere he come, that a swift blessing

may soon return to the our suffering country

under a hand accursed!"

3.6.49-53

This religious imagery makes Macbeth seem like Satan, and Malcolm and his followers a godsend. This links to the theme of the difference between tyranny and kingship, as a real king is ordained by God (like Malcolm is and Macbeth clearly isn't).