I have a question regarding Act 5 of Macbeth.As it happens, Malcolm brings "Great Birnam Wood to High Dunsinane Hill" and Macduff reveals that he was "not of woman born" but was instead "from...

I have a question regarding Act 5 of Macbeth.

As it happens, Malcolm brings "Great Birnam Wood to High Dunsinane Hill" and Macduff reveals that he was "not of woman born" but was instead "from ...[his] mother's womb untimely ripped." But how is the manner of these fulfilments ironic, considering the significance Macbeth attached to them when he heard them during his second meeting with the Weird Sisters?

Expert Answers
Noelle Thompson eNotes educator| Certified Educator

The manner of these fulfilments certainly is ironic, in all cases!  Let us take Macbeth's reaction to the second apparition to heart.  Macbeth has just been told that "none of woman born / Shall harm Macbeth" (4.1.80-81); therefore, responding Macbeth says the following:

Then live, Macduff; what need I fear of thee? / But yet I'll make assurance double sure, / And take a bond of fate. Thou shalt not live. (4.1.82-84)

In other words, by reacting to the second apparition, Macbeth is already disregarding the first!  Although he has just been told to "beware Macduff," Macbeth admits he needs not fear him both because he is sure that Macduff is of woman born and also because Macbeth is planning to have Macduff killed.  Further, it is ironic because Macbeth finds out the truth about Macduff while trying to take his life.

In regards to the third apparition, the manner in which it is fulfilled is also ironic. Macbeth has just been told by the witches that he cannot be killed until "Great Birnam Wood to High Dunsinane Hill / Shall come against him" (4.1.92-93).  Macbeth's reaction?

That will never be. / Who can impress the forest, bid the tree / Unfix his earth-bound root? (4.1.94-96)

Who can, Macbeth?  I'll tell you who can:  Malcolm!  Again, Macbeth dismisses the witches' answer in his own arrogance and ambition.  The irony here is the witches' warning is exactly what happens when Malcolm has his soldiers cut boughs from Great Birnam Wood to camouflage the advance.  Thus, in all of the aforementioned ways, the fulfillment of these prophesies is very ironic.