Final answer:
Macbeth says he killed Duncan's guards out of a rage sparked by his love for Duncan and by seeing the guards seemingly caught red-handed, which overwhelmed his reasoning.
Step-by-step explanation:
Macbeth's statement about why he killed Duncan's guards is driven by his intense emotions and illogical reasoning. He suggests that seeing Duncan's murdered body and the blatant guilt of the guards, with their hands and daggers 'unmannerly breech'd with gore,' spurred him into a rage. Macbeth describes that his 'violent love' for Duncan and the shock of the scene overwhelmed his sense of reason ('Outrun the pauser, reason'), making it impossible for him to act wise, or temperate. This love and passion drove him to act without thinking, claiming that no one who loved Duncan and had the courage to act on that love could have refrained from killing the guards.