In addition to the other editors' posts about personification, Macbeth's quote in Act II, scene ii of Macbeth is a metaphor (an analogy), and it is filled with two types of imagery.
Metaphor / Analogy: Translated, it means, "sleep that straightens out the tangled coil of worry." Macbeth and his wife have murdered Duncan and sleep, so Macbeth is comparing the act of sleep to to the act of unravelling. Sleep unravels worry the same way a weaver unravels thread. He will not sleep for the rest of the play; instead, he will forever worry and be paranoid that someone or something supernatural will discover his crime.
Imagery: the line contains two types of imagery: "sleep" and "clothing." The leitmotif of sleep runs throughout the play. The lack of sleep is a result of guilt, and it will drive both Macbeth and Lady Macbeth crazy by the end of the play.
Macbeth is also full of clothing imagery: "borrowed robes," the "crown," and "the sleeve." These images underscore the domestic and gender differences between the couple. Ironically, Macbeth makes an analogy here about a feminine domestic duty (sewing).