In Act IV, Scene I, Shakespeare is referring to a red letter day (any day of special significance) when Macbeth states, “… Let this pernicious hour stand aye accursed in the calendar!” (149 – 150).* Macbeth is referring to the news from the witches that tell him of eight kings descended from Banquo (instead of Macbeth.) The witches tell Macbeth many things that he cannot understand; yet, the witches are telling Macbeth the truth…
In Act III, Scene I of William Shakespeare’s "The Tragedy of Macbeth," Banquo tells Macbeth that he will ride as far as he can before supper. The word “twain” derives from the Old English word twegen, simply meaning “the number two (2).” Essentially, Banquo states that he will be riding in the dark an hour or two if his horse is slow. (Poets frequently use “twain” instead of “two” at the ends of lines for rhyming purposes.)
Composed probably in 1606, Shakespeare’s use of the word “epicure” in "Macbeth" is particularly interesting because at that time, “epicure” was considered “archaic” that is, rare in the early 1600s present-day usage. The meaning of Shakespeare’s “epicure” is taken from the philosophy of an ancient Greek philosopher, Epicurus (341–270 B.C.E.) An “epicure” is a person that disbelieves in God (the divine government of the world,) and in an afterlife spent in either Heaven or Hell; this is also a person who recognizes no religious motives for conduct.
For the effect of sensationalism, William Shakespeare frequently used ghosts in his plays.