­1. Is this a dagger which I see before me,
The handle toward my hand? Come, let me clutch thee.
I have thee not, and yet I see thee still.

In this quote we see the first time that Macbeths mind and mental state is questioned in the play. Here, Macbeth has a hallucination where he thinks that he sees a sword. This represents how guilty Macbeth feels that he is gonna kill Duncan and his mental deteriation.