Shakespeare employs many literary devices throughout Macbeth, and especially in Act 2, scene 3, after Duncan's murder has been discovered.
Macbeth responds to the details of the murder with telling figurative language as he describes the crime scene "his gash'd stabs look'd like a breach in nature, for ruin's wasteful entrance" (113-114). Using simile, he compares the unnatural, violent quality of Duncan's death to a breach and the stab wounds to a gateway for decay.
This particular scene also incorporates imagery, diction, and detail to make the violence of Duncan's death even more vivid. Macbeth in his disturbing account finds "the murderers, Steep'd in the colors of their trade, their daggers Unmannerly breech'd with gore" (114-116). The connotation of the word "steep'd" suggests that the murderers were drenched in blood, since the "colors of their trade" would be crimson. These lines by Macbeth use personification as well, describing the daggers as "breech'd with gore," like the daggers wore red, gory pants.
Shakespeare's varied use of literary devices makes Duncan's murder scene even more violent and horrifying.
Shakespeare loves to create vivid figures of speech to help get his meaning across. The play Macbeth is no exception. He is able to make them so often that we easily do not realize that we are reading metaphors, similes, and personification unless we stop and read carefully.
In addition to the examples in the above answer, we have several metaphors. In line 92, Macbeth is talking to Donalbain about the fact that his father, King Duncan, has been killed:
. . . the fountain of your blood
Is stopped; the very source of it is stopped.
Fountain here refers to King Duncan, because he is the one who gave Donalbain life. As a fountain pours forth with water, Duncan poured forth his blood to create Donalbain.
In line 96 Lennox is describing the appearance of the guards who have just been discovered dead and bloody. They are being blamed to Duncan’s murder:
Their hands and faces were all badged with blood;
The key word here is “badged,” which means “marked.” By using the word badge we imply that the blood identifies (like a badge would) the identity of the killers and is therefore a metaphor. Shakespeare could have just said that the guards were bloody, therefore they were probably the killers, but that would have been less dramatic and made less of an impression on the reader.