In a thorough literary analysis, a “ravell’d sleave” is a tangled string of thread or yarn. Macbeth makes a clever metaphor for the kind of frustration one experiences when they have so many problems that they can’t see the end to any of them. In many instances, people often say that they want to “sleep on it” in order to get everything straight in their head. To Macbeth, sleep is not only a necessity of life, not only part of one’s health, but something that makes life worth living, and sadly he feels that when he murdered his King in his sleep, he murdered sleep itself. When Macbeth thought he heard voices that told him he’ll never sleep again he became anxious and apprehensive.