Personification is a literary device that gives human characteristics to...
In Shakespeare's Macbeth, Act Four, scene three, we see imagery (in general) and personification (specifically) used by the author to clarify the feelings of Malcolm, the Prince of Cumberland and heir to the Scottish throne, in the play.
Personification is a literary device that gives human characteristics to nonhuman things. Imagery is the use of descriptions, often using sensory images (or images that appeal to the senses) (or similes or metaphors) to create vivid pictures in one's mind of what is being described.
In Malcolm's speech, imagery is used as he describes how the country "feels" beneath the murderous oppression of Macbeth:
I think our country sinks beneath the yoke... (45)
This is not personification because the country is being compared to an animal (like an ox) used for farming—not compared to a man.
However, in the next line, personification is used, comparing the country to a wounded person:
It weeps, it bleeds, and each new day a gash
Is added to her wounds. (46-47)
A country cannot weep or bleed, or be literally wounded, as a person can.
As Malcolm continues to test Macduff's true loyalty to Scotland, Duncan's son notes that even when Macbeth is beaten, Scotland will suffer more than before because Malcolm (the heir to the Scottish throne) is worse than Macbeth (or so he says—he is not sincere). Once again, personification is used:
...yet my poor country
Shall have more vices than it had before,
More suffer and more sundry ways than ever,
By him that shall succeed. (52-55)
Again, a country cannot have a vice. A country also cannot not suffer, so this, too, is a human experience given to something not human.
Lastly, Malcolm (again as part of his "test" of Macduff) admits that when his vices are known, Macbeth will seem like a lamb by comparison.
That, when they shall be open'd, black Macbeth
Will seem as pure as snow, and the poor state
Esteem him as a lamb, being compared
With my confineless harms. (59-62)
In general, imagery is used again. However, specifically, Shakespeare uses a simile in comparing Macbeth to a lamb, the inference being that Macbeth will be like an innocent lamb when compared to Malcolm who (he says) has many more sins weighing upon him than Macbeth.
(Macduff compares Malcolm to a devil, as well, but this is a metaphor, not personification.)
Once Macduff admits that Malcolm is not fit to live let alone to govern with all these sins upon him, and Macduff mourns the future of Scotland, Malcolm knows for certain that Macduff has come to save Scotland and not to spy for Macbeth. At this point, Malcolm tells Macduff the truth: that the Prince of Cumberland is a chaste and honest man.