Hang out our banners on the outward walls;
The cry is still “They come:” our castle’s strength
Will laugh a siege to scorn.

– William Shakespeare

Macbeth, Act 5, Scene 5. Macbeth shows signs of mental instability as well as arrogance and reckless bravado. The enemy troops are approaching his castle and yet he defiantly dares them to come, thinking that he is invincible. He has deceived himself by believing what the Witches have told him and that their prophecies somehow offer protection to him from all enemies. His hubris and boastful superiority is on full display in “our castle’s strength Will laugh a siege to scorn.” This is also an excellent example of personification.