Filthy hags!
Why do you show me this? A fourth! Start, eyes!
What, will the line stretch out to the crack of doom?
Another yet! A seventh! I’ll see no more:
And yet the eighth appears, who bears a glass
Which shows me many more; and some I see
That two-fold balls and treble scepters carry.

– William Shakespeare

Macbeth, Act 4, Scene 1. When the Witches show Macbeth their fourth apparition of a procession of kings descended from Banquo, he is clearly upset and angry. He asks if Banquo’s lineage will continue to occupy the throne until the end of time. Foreshadowed here is Banquo’s children having power.