Here Macbeth questions whether he is really seeing the dagger. This is when he starts hallucinating.

These last words before the ringing of the bell suggest that Macbeth was close to talking himself out of killing Duncan, as his courage was fading as he continued to obsess over the phantom dagger. The intense illusion is shattered by Lady Macbeth's signal that Duncan's guards are asleep, and Macbeth immediately leaves.

In attempting to explain his vision, Macbeth wonders if his heat-oppressed, or feverish, brain is the cause. During the Renaissance, heat in the body was considered a fluid that could actually press on the brain, causing fever and delirium.

Sextus Tarquin was the youngest son of the last king of Rome, Lucius Tarquinius Superbus, whose rape of Lucretia led to the overthrow of the Roman monarchy. The adjective ravishing here is applied to the strides to emphasize how quickly Murder moves.

This is an example of personification, attributing human qualities to non-human or abstract things, in which the act of Murder is portrayed as a thin and ghostlike man.

Hecate is a Greek goddess who presides over magical rites and is associated with witchcraft, the night, and the underworld. Her mention here in Macbeth's soliloquy is important considering later developments in the story with the three witches.

The illusory dagger becomes covered in blood as Macbeth continues to watch it. This vision adds another supernatural element to the play with symbolic meaning: It represents Macbeth's inner turmoil and feelings of horror about the murder he is about to commit.

In this context, the adjective fatal refers to the vision as something sent by fate rather than a vision that is deadly. As Macbeth struggles with this vision, he considers why he is seeing is and what it means.

Seeing that nothing is to be gained from Banquo, Macbeth ends the conversation. However, even these innocent words are full of innuendo as Banquo and Macbeth both have an idea of whose side they are on, making them very suspicious of one another.

Macbeth's underlying intent here (in fact, this dialogue is full of subtext) is to discretely offer Banquo an opportunity to join Macbeth's side. Since Banquo brought up the witches, Macbeth is using this opportunity to see if he has an ally or an enemy in Banquo.

Notice here how Macbeth somewhat uses the royal "we" in this passage and refers to himself in the plural. In doing so, he speaks as if he were already crowned king.

"Largess" refers to gifts or generosities that the King bestowed on Macbeth and his servants. These gifts not only explain why it was so easy for the entire castle staff to drink and feast, but they also help to carry our Lady Macbeth's initial plan to get Duncan's bodyguards drunk. However, this excess of gifts and drink has repercussions for Macbeth in the morning.

Banquo's immediate reaction upon seeing Macbeth's torch is to prepare himself for a fight. Even though he is a guest in Macbeth's castle, the lateness of the hour and the agitated state of Banquo's mind are likely explanations for this behavior. His response also helps to build up the tense atmosphere in the castle before Duncan's murder.

This simile tells the audience how tired Banquo is: he feels the call of sleep ("a heavy summons") weighing on him ("like lead") and making him tired. However, he ignores the call, for reasons we shortly learn in his conversation with Macbeth.

Banquo might be making a joke to amuse his son to state how dark it is: Heaven is trying to be economical ("there's husbandry") with their lights (candles). This also contains an interesting idea—that the lights in the sky are all candles used by the inhabitants of heaven to light their homes.

Here, a “Torch” may indicate an attendant bearing a torch, rather than the torch itself. Since the play would have been performed in broad daylight, the "torch" would be used as a prop to suggest that it was night. Additionally, Banquo and Fleance establish that the time is somewhat later than midnight.

Lady Macbeth will not strike upon the bell to signal that Macbeth's drink is ready. He just says this to deceive the Servant. Lady Macbeth will strike upon the bell to signal that Duncan's two grooms have been successfully drugged and now the coast is clear for her husband to go into Duncan's chamber and murder him.

Macbeth personifies Murder and then calls the wolf Murder's sentinel. The wolf's howl is equated with the a watchman's call, or "watch," as he makes his rounds.

Banquo is afraid to fall asleep because he is aware that he is capable of having evil thoughts in the form of dreams. He is not entirely lacking in ambition. He has been promised that he will be the sire of a whole line of Scottish kings, and naturally he wants this to happen. In his dreams he must be imagining the ways in which this might come about. It is hard to see how it could happen without the deaths of Duncan, Malcolm, Donalbain, and Macbeth. The witches only told him "what" and not "how." Macbeth has taken it upon himself to expedite his part of their prophecy by committing murder. No doubt the three Weird Sisters figure in some of Banquo's "cursed thoughts." In fact, he tells Macbeth: "I dreamt last night of the three weird sisters." They may even be telling him to commit murders. With their contradictory prophecies they have spoiled the friendly relationship that existed between Banquo and Macbeth. When the two men meet in this scene they will both be wary and suspicious.

This opening dialogue between Banquo and his son Fleance is solely intended to establish that the time is late at night. Shakespeare’s audience would have to imagine it as dark, although they would be watching the play in an open-air theater in broad daylight. Modern theater companies often perform Shakespeare’s plays in public parks in the daytime, and their audiences have to imagine this scene is occurring at night, just as was done by Elizabethans.

This is probably said with a big smile—but it is innuendo. Macbeth is saying, in effect, that he is well aware that Banquo is afraid to go to sleep and that he had better not interfere with what he strongly suspects to be Macbeth's intention to murder Duncan or he will be next. This brief meeting between these two warriors is masterfully conceived and executed. They have discussed a great deal—past, present and future—without putting anything into plain words.

These two men have become suspicious of each other ever since they heard the witches' prophecies. It is significant that Banquo is carrying a sword in his host's castle. Shakespeare calls attention to the weapon by having Banquo give it to his son and then take it back from the boy when he sees figures approaching in the darkness. He apparently keeps his hold on the sword throughout his conversation with Macbeth. Macbeth is possibly already thinking that he will have to dispose of Banquo if he wants to keep the Scottish crown in his own line of succession. Banquo knows what Macbeth must be thinking. Each man is afraid to go to sleep because the other has a strong motive for murdering him in his bed.

Banquo seems to be suspicious of Macbeth and a little afraid of him. Here he is trying to sound Macbeth out about his thoughts and feelings. Macbeth takes Banquo's mention of the weird sisters as an invitation to talk about a possible joint conspiracy against Duncan—but he is wrong. Banquo doesn't trust Macbeth and is loyal to Duncan. If his heirs are to become kings, this will have to come about in a natural way. He is content to be patient and watchful.

This is almost comically ironic. Macbeth is Banquo's worst enemy and will soon be responsible for his murder.

Shakespeare wants to call attention to the fact that Banquo is carrying a sword. This seems a little strange, since he is a guest in a friendly castle. Banquo must be feeling apprehensive. No doubt he has been thinking about the witches' prophecies. If Macbeth were to become king, Banquo and his son might be in great danger; Banquo can see that Macbeth would be capable of violence to prevent Banquo from siring a whole line of heirs to the Scottish throne. Banquo may feel that his and Fleance's lives could be in danger even now, since they are in Macbeth's power. Banquo might even have a foreboding that Macbeth might be capable of committing multiple murders, or having them committed, that very night—disposing of Duncan, Malcolm, Donalbain, Banquo, and Fleance while he had this golden opportunity to do so.

Though the play would be peformed in daylight, Shakespeare endeavors to create the feeling that it is the dead of night. Banquo and Fleance have a lighted torch. Fleance mentions that the moon has gone down, and his father says that it goes down at midnight. Then Banquo observes that the inhabitants of heaven have put out all their candles (i.e. all the stars), which further contributes to the illusion of night and darkness. 

Why should Banquo want his sword when he is a guest inside Macbeth's castle? Is he already thinking that Macbeth might want to try to prevent him from siring a whole line of Scottish kings? Duncan and his two sons are at Macbeth's mercy while sleeping under his roof. But Banquo and his son Fleance are also vulnerable—and Banquo knows it! Perhaps that is why Banquo hasn't gone to bed. He may be planning to stay awake all night and then leave tomorrow. 

Macbeth is hinting that he would like to talk to Banquo about how they could cooperate in making the witches' prophecies come true. It would mean killing Duncan and his two sons, as they both know. Macbeth would only bring this subject up at this time because he has Duncan, Malcolm, and Donalbain under his roof for one night only, and he would very much like to have some help in committing three murders. However, Banquo is not only loyal to Duncan but has no desire to make Macbeth king. Banquo is also skeptical about the witches' promises and realizes that if he helps Macbeth become king through disposing of Duncan and the two legitimate heirs to the throne, he himself would probably be next on Macbeth's assassination list. If Macbeth is treacherous enough to kill the king and his two sons, he could also be treacherous enough to pin all three murders on Banquo.

This is intended to explain to the audience something that will come up later. Macbeth will be forced to come out of his bed chamber because of a persistent unanswered knocking. It turns out that it is Macduff doing the knocking because he was appointed to wake King Duncan. This brings the protagonist and antagonist together for the only time before their death duel at the end. But why was Macduff, an important thane, forced to spend the night in a hovel outside the castle? Macbeth explains to Banquo that they were "unprepared" to accommodate so many guests. This is a weak explanation. Why didn't Duncan order someone who would be sleeping inside the castle to wake him? But it is the best Shakespeare could think of if he wanted Macduff to be doing all the knocking and Macduff to discover the King's murdered body. Shakespeare also wanted Macbeth to be present when he did. That is the explanation of the long, persistent knocking which Thomas De Quincey writes about in his famous essay "On the Knocking at the Gate in Macbeth." Macbeth has to stop playing possum and come down to find out why nobody is opening the gate. 

This quote illustrates foreshadowing (a clue as to what may come). Macbeth "seeing" the dagger foreshadows the manner by which Duncan will die and Macbeth's coming hallucinations. The bloody dagger becomes a symbol for Macbeth's rampant ambition.

The suggestion here is that Banquo too is feeling temptation from the witches prophesy when he lies down to sleep. However, the audience also understands that he has not yielded to such temptation because of help from "merciful powers" (something like guardian angels).