In "Macbeth", quote the word Banquo says that tells you how Macbeth reacts to the witches?

BANQUO: Look, how our partner's rapt.

This is the bit you're thinking of, I think. Banquo is noticing that Macbeth has been dreaming to himself (in fact, delivering an aside to the audience) since the witches spoke, and describes him as "rapt" (or "enraptured").

Hope it helps!