How does Malcolm's army fulfill the witches prophesy?

Malcolm's army fulfills the witches' prophecy by advancing on Macbeth's castle while carrying branches from Birnam Wood, which aligns with the prophecy that Macbeth will fall when Birnam Wood comes to Dunsinane. This clever tactic disguises their true numbers and creates the illusion that the forest is moving. Additionally, Malcolm's ascent to the throne after Macbeth's defeat reflects the prophecy's foretold end of Macbeth's reign, restoring order to Scotland. Thus, the witches' predictions come to fruition through Malcolm's strategic actions and the eventual downfall of Macbeth.