Though his bark cannot be lost,
Yet it shall be tempest-toss’d.
– William Shakespeare
Macbeth, Act 1, Scene 3. The witch plotting revenge on a sailor knows that she cannot destroy his ship, but she can call up storms to disrupt his voyage. This shows that while the Witches can use their powers to influence events, they are not all-powerful and cannot completely control a person’s fate. Foreshadowed here is how the Witches will influence Macbeth through their prophecies, but cannot force him to act. Macbeth by exercising his free will and through his own actions will end up dooming himself.