As sparrows eagles, or the hare the lion.
Act I, Scene 2
Context
Duncan asks whether the arrival of Norwegian reinforcements frightened Macbeth and Banquo; the Captain answers with this compressed comparison to dismiss the idea.
Analysis
The elliptical syntax strips the comparison down to its bones—'As sparrows eagles'—forcing the audience to mentally complete 'as much as sparrows frighten eagles.' This verbal shortcut mimics the speed and certainty of the Captain's answer, as if the notion of Macbeth feeling fear is too absurd to warrant a full sentence.
Essay Tip
Use this to argue that the play's early scenes construct Macbeth as a figure of absolute martial confidence, making his later paranoia and fear-driven murders a dramatic reversal—he becomes the sparrow, not the eagle.