If a man were porter of hell gate, he should have old turning the key.
Act II, Scene 3
Context
The Porter, drunk and woken by knocking at the castle gate in the early morning, imagines himself as the gatekeeper of hell admitting sinners.
Analysis
The Porter casts himself as gatekeeper to 'hell gate,' a choice that transforms Macbeth's castle into an infernal space just after Duncan's murder. This diction works by letting a minor character say what the play cannot yet announce directly: that Inverness has become a place of damnation. The casual, drunken tone makes the metaphor feel accidental, which is exactly what allows it to land as truth.
Essay Tip
Use this to argue that Shakespeare uses the Porter scene not as comic relief but as a way to name what Macbeth's actions have done to the space itself—the castle is now literally hell's entryway, and everyone who enters is complicit or damned.