Returning to the same word, phrase, or construction, at the start of successive verses or sentences (anaphora) or throughout the text, to give rhythm, emphasis, or insistence.
In Macbeth
O, treachery! Fly, good Fleance, fly, fly, fly! / Thou mayst revenge.
The verb "flee" appears three times in a row, in the haste of someone with a single moment to speak. The repetition gives Banquo’s cry the urgency of an order shouted in the dark, one step from death.
Act III: The King Ruled by Fear, Banquo
Macbeth, Macbeth, Macbeth! Beware Macduff; / Beware the Thane of Fife.
Act IV: Deceptive Prophecies and Massacre, the first apparition, an armed head
He has no children. All my pretty ones? / Did you say all? O hell-kite! All? / What, all my pretty chickens and their dam / At one fell swoop?
Act IV: Deceptive Prophecies and Massacre, Macduff
Tomorrow, and tomorrow, and tomorrow, / Creeps in this petty pace from day to day, / To the last syllable of recorded time; [...] Life's but a walking shadow, a poor player / That struts and frets his hour upon the stage / And then is heard no more. It is a tale / Told by an idiot, full of sound and fury, / Signifying nothing.
Act V: Sleepwalking, Birnam, and the Fall, Macbeth
Subscription
The explanation of each passage, in every device and in every work, comes with a subscription.