Macbeth, Act III

“O Proper stuff! This is the very painting of your fear.This is the air-drawn dagger which you said Led you to Duncan.” Lady Macbeth tells Macbeth that his hallucination of seeing the ghost of Banquo is nonsense.
“Thou has it now- King, Cawdor, Glamis, allAs the weird Women promised, and I fearThou played’st most foully for ‘t” Banquo accuses Macbeth of using foul play to gain the title of King.
“I am I in bloodStepped in so far that, should I wade no more,Returning were as tedious as go o’er” Macbeth tells Lady Macbeth that he has committed too many crimes to turn back now. He must continue to commit murder to assure his own safety.
“To be thus is nothing, But to be safely thus. Our fears in BanquoStick deep, and in his royalty of natureReigns that which would be feared.” (soliloquy) Macbeth says that being a king is worthless because his position (as king) is not safe. He feels threatened by Banquo because he is of natural nobility and can take his place as king.
“Better be with the dead, Whom we, to gain our peace, have sent to place, Than on the torture of the mind to lie” Macbeth is speaking to Lady Macbeth. She asks him why he looks so troubled. He admits that he would rather be with the dead so that he would not have to live with the anxiety and nightmares that he has been having.