The weird sisters, hand in hand,
Posters of the sea and land,
Thus do go about, about:
Thrice to thine, and thrice to mine,
And thrice again, to make up nine.
– William Shakespeare
Macbeth, Act 1, Scene 3. As the three Witches prepare to meet Macbeth, they chant a spell to call up a storm and hamper the voyage of a sailor whose wife has insulted one of them.