There are many examples

There are many examples.

These include the imaginary dagger appearing, Banquo's ghost appearing and Lady Macbeth trying to get rid of the imaginary bloodstains.

There is a physicality to these examples. However examples of pure literary imagery include the links between Macbeth and the witches. For example "So fair and foul a day I have not seen " Macbeth, linked with "Fair is foul and foul is fair" the witches. Also "By the pricking of my thumbs something wicked this way comes" a witch's reference to the approach of Macbeth.