Third Witch
That will be ere the set of sun.
First Witch
Where the place?
Second Witch
Upon the heath.
Third Witch
There to meet with Macbeth.
Though never directly confirmed within the play, the weird sisters certainly have some unnatural tricks hidden up their ragged, draping sleeves. They accurately pinpoint Macbeth’s future location, as well as predicting the end of the battle, "ere the set of sun". This also hints towards the current position of the plot; the sunlit times before the night of Duncan’s cruel slaughter, and Macbeth’s dark, deteriorating descent.
The sisters’ stichomythic speak is in a strange, spellbinding rhythm, not to just make things eerie, but also to tell us of their solidarity as sisters. So, when the name "Macbeth" finally comes and breaks this rhythm with an extra syllable, it is immediately made significant.
- Ken
The witches stir up a pot of “truth” to give Macbeth false hopes about his future as king. This is an explicit demonstration of the tricks up their sleeves, thus a direct example of their powers. Baboon blood? Where does one buy that?