Lady Macbeth uses this speech to calm Macbeth's guilty conscious. However, her flippant response to Macbeth's worries, essentially there's no changing what has happened so forget about it, comes back to haunt her when she begins to feel pangs of guilt. Her "what's done is done" later transforms into "what's done cannot be undone," as Lady Macbeth becomes overrun with guilt.

Macbeth calls on the coming of night to carry out the destruction of the "great bond" that worries him so. The choice of this word "bond" relates to Lady Macbeth's earlier use of "copy" to refer to the lease that Banquo has on life. Macbeth wants the night and his plans to tear up this lease (kill Banquo) to free him from worry.

A "chuck" refers to a chick or chicken and at the time was a familiar term of endearment for spouses, children, or other close companions. In addition to calling Lady Macbeth "love," these are some of the most tender words he's used with her in the play, which is conspicuous considering he has not told her his plan for Banquo.

That is, dangerous and threatening thoughts plague Macbeth's mind and the fact that Banquo and Fleance live is a constant reminder of the witches' prophesy.

The word "copy" in this instance has a technical meaning associated with law ("copyhold"), and refers to a kind of lease for land or property. Lady Macbeth is essentially saying that they do not have an eternal lease on life; that is, they will die eventually. Notice, however, that Lady Macbeth's suggestion here reveals just how little she knows of her husband's plans, hinting at committing a crime that he has already planned out.

The reasons for why Macbeth tells his wife to heavily praise and favor Banquo are unclear. He has not told her about his plans to have Banquo murdered, so these words are possibly designed to deceive her. Another reason, although less likely, is that he knows there is a chance the plot would fail, and he wants her to act naturally.

Despite her own worries, Lady Macbeth rallies to support her husband. She addresses him in tender tones to try and ease his mind. While he initially responds well to this, he resumes brooding shortly after.

In a way very characteristic of his style, Shakespeare plays on the word "peace" by putting two instances close together with multiple meanings. The first instance refers to the satisfaction of Macbeth's desire for power that he had hoped to gain by killing Duncan; and the latter instance refers to the peace of death.

Recall how on the night he murdered Duncan, Macbeth claimed to hear a voice proclaiming that he would sleep no more. It appears as if he is realizing the prophetic meaning or that imaginary voice, as his worries prevent him from sleeping.

Notice how these lines parallel Lady Macbeth's earlier in the scene. It is clear that the both of them constantly worry about their security and almost envy the peace of the dead. Nowhere else does Macbeth give us a clearer vision of his own "restless ecstasy," by which he means "madness," than here where he envies the peaceful sleep of Duncan.

"Malice" typically means a desire to cause harm to another living being. In this case, Macbeth calls it "poor" malice to signify a weak desire to do harm. The implication is that a weak will to commit necessary evils will not benefit and likely harm Macbeth and his wife.

The choice of "tooth" here implies that the snake, if left to recover, would regain its "former" (prior to being "scotch'd") power to bite. Macbeth wants to ensure that the dangers he and his wife has will not grow in strength and return to harm them.

This line represents a common belief at the time that snakes, even those that were severely harmed, could eventually recover from the injuries and the wounds would close. Macbeth is saying that their "snake" will return to full strength unless it is fully destroyed.

This expression means to render something temporarily harmless or less harmful without completely destroying it. The snake serves as a metaphor for anything or anyone who is problematic, dangerous, or undesirable.

In the second rhyming couplet of these four lines, Lady Macbeth continues to express her discontent with their situation. She states that sharing the same fate as those they have destroyed (killed) would be better than endlessly worrying about their future and never being truly happy.

This scene gives us an important look at Lady Macbeth. She reveals herself as less confident when not around her husband, wondering why she is not content even though they have achieved their goal. They have invested everything to get the throne, but it has no meaning unless they are happy and satisfied.

This line indicates that Lady Macbeth has no knowledge of Macbeth's plans to have the murderers kill Banquo. She likely believed that he dismissed the court in order to have time alone to think about the murder of Duncan. She shortly chastises him for doing so, saying that nothing can be changed about it, so it is not worth thinking about. ("What's done is done.")

Notice how Banquo is on Lady Macbeth's mind. Since she knows his part of the witches' prophesy, it's possible that she also fears for the security of Macbeth's throne and is thinking of ways to prevent the prophesy from coming true.

What Macbeth says seems paradoxical: life itself is a sickness from which we recover by dying, after which we will sleep comfortably. Note the alliteration of "F" sounds in "after," "life's," "fitful," and "fever," intended to emphasize the stress, anxiety, and wasted effort, i.e., the fitfulness and feverishness, involved in living. There are actually six "F" sounds in "after life's fitful fever," because the "V" in "fever" will sound like an "F."