Macbeth is an equivocator in Act 1 Scene 7. ‘I have no spur to prick the sides of my intent, but only Vaulting ambition which o’erleaps itself and falls on th’other’ He is saying he has no motivation to kill Duncan apart from his own ambition to be king. Shakespeare uses a metaphor he is saying his intent is a horse by saying ‘I have no spur to prick the sides of my intent.’ His spur is his motivation as if he cannot spur his horse on.