Double, double toil and trouble
Witches:
Double, double toil and trouble
Fire burn, and cauldron bubble.
Three Scottish witches are going about their business—tossing poisoned entrails, eye of newt, toe of frog, and such, into a cauldron—while awaiting a visit from the man they said would be king: Macbeth. "Double, double toil and trouble" is part of the refrain to their demonic incantation, an inspiring little number in tetrameter (four accents per line). The collective memory has clouded somewhat; often, this refrain comes to mind in the jumbled form "Bubble, bubble, toil and trouble," which makes even less sense than the original. The witches are actually trying, with their spells, to pile up toil and trouble until they "double"—yielding twice the toil and double the trouble for Macbeth, presumably.