“What, can the devil speak true?”AllusionAct 1,Scene 3Line 108bAn explanation of the proverbial reference, “What, can the devil speak true?” in Act 1, Scene 3 of myShakespeare’s Macbeth. Banquo Ross Angus Ross Banquo What, can the devil speak true? This line is a riff on the old proverb, “the devil sometimes speaks the truth.”