"When shall we three meet again? In thunder, lightning, or in rain?...Upon the heath" (1.1.1-7). The witches are discussing when and where they will meet Macbeth and Banquo.
All hail, Macbeth! Hail to thee, thane of Cawdor... that shalt be king hereafter! ...Hail! Lesser than Macbeth and greater. Thou shalt get kings, though thou be none. So all hail, Macbeth and Banquo. (1.3.50-70). The witches are explain their prochecy's of Banquo and Maceth.
The prince of Cumberland! That is a step. On which I must fall down, or else o'erleap. Stars, hide your fires; Let not light see my black and deep desires (1.4.50-53). After hearing that Malcolm is the heir to the throne, Macbeth contemplates about how he's in the way and what Macbeth must do.