In Act 5, Scene 7, Macbeth is confronted by Young Siward, son of the Siward who is the commander of the English forces. They fight with swords and Macbeth kills his opponent. Then he boasts
Thou wast born of woman.
But swords I smile at, weapons laugh to scorn,
Brandished by man that's of a woman born.
Shakespeare seems to be showing in dramatic fashion that Macbeth is courageous, that he is still a formidable opponent, and especially that he is still relying on the promises of the witches that no man of woman born can overcome him. The audience needs to be reminded of this prophecy in order for Macduff's astonishing revelation to be fully effective when the two men confront each other a short time later. When Macduff says "Despair thy charm, / And let the angel whom thou still hast served / Tell thee Macduff was from his mother's womb / Untimely ripped," Macbeth knows he is defeated. He actually says, "I'll not fight with thee." But Macduff uses scornful language to force him to fight. Characteristically, Shakespeare uses words rather than actions to dramatize Macbeth's defeat. The actual fight occurs mostly offstage.