In Act V scene 7, Macbeth describes his situation by refering to himself as a bear who has been staked and is now being baited. This comes after the news of the woods of Dunsinane coming towards his castle, which of course fulfills one of the prophecies of the witches that indicates his imminent downfall. Examine carefully what Macbeth says in response to this:
There is a real sense in which fate is refered to here. It is uncertain who "They" are, but it is clear that whether it is the forces of fate, the witches or Malcolm's army, they have taken away Macbeth's ability to flee and escape and he has to face his destiny in the battle that is to come. As we can see from this quote, however, Macbeth is still confident and trusting in the words of the witches.