Here’s a knocking, indeed! If a man were porter of hell-gate he should have old turning the key. Knock, knock, knock! Who’s there, i’ the name of Beelzebub? Here’s a farmer that hanged himself on the expectation of plenty.

– William Shakespeare

Macbeth, Act 2, Scene 3. In what is popularly known as the Porter Scene, the drunken Porter answers a knocking at the gate of Macbeth’s castle, playing the role of a porter at the gates of hell. In his soliloquy he tells a knock knock joke about a farmer who hanged himself. The light-hearted interlude is meant to break the tension after the violent happenings at the castle. There is dramatic irony in the Porter’s words, because what he doesn’t know is that he is actually at the gates of hell after Macbeth’s murder of King Duncan at the castle.