Macbeth Act 1, Scene 7
Within the castle, Duncan eats and Macbeth leaves dinner to be off on his own. Macbeth is rethinking the plot to kill Duncan when Lady Macbeth comes in. She asks her husband why he's left dinner. Guessing at his fears, she tells him that he is a coward if he doesn't go through with the plan to kill Duncan while he sleeps, framing the drugged guards outside the king's bedroom. She tells her husband to "screw [his] courage to the sticking-place." Act 1, Scene 7, line 60 After this goading Macbeth agrees to kill Duncan that night and make himself king.