Macbeth shall never vanquished be until
Great Birnam wood to high Dunsinane hill
Shall come against him.

– William Shakespeare

Macbeth, Act 4, Scene 1. The Witches continue their deceitful nature with their third apparition, a child crowned, with a tree in his hand. The child’s prophecy may at first appear to suggest that Macbeth is invincible. And this is exactly what he believes. In response he says: “That will never be Who can impress the forest, bid the tree Unfix his earth-bound root.” But the apparition’s words turn out to be ironic and foreshadowing, because it is Macbeth’s fate to be defeated just as the prophecy describes.