I must become a borrower of the night
For a dark hour or twain.

– William Shakespeare

Macbeth, Act 3, Scene 1. Light and dark imagery is used throughout Macbeth to symbolize good and evil. Here Banquo tells Macbeth that he will be riding in the dark for an hour of two after sunset, providing the perfect opportunity to have Banquo murdered. Banquo’s death is foreshadowed in his own words.