The purpose was to predict what's going to happen. It was a foreshadow that Banquo will be lesser than Macbeth and greater as well. The weather sets the mood, the witches hails him "Thane of Glamis," <span>"Thane of Cawdor," and that he shall "be King hereafter" also.</span>
The first scene in the play is to foreshadow the coming scenes and how Macbeth will be king.
Explanation:
The first act of the play "Macbeth" by William Shakespeare shows the three witches predicting the rise of Macbeth first as Thane of Glamis and Cawdor and then he will become the king of Scotland. It also shows the prediction for Banquo's rise as well, with his future generation becoming the king of Scotland. This scene/act acts as a foreshadowing for the upcoming scenes. It foreshadows and predicts how Banquo will be lesser than his friend Macbeth but at the same time be greater than him too.
