The scene begins in a light and humorous mood. The porter — still intoxicated from the previous night’s drinking — playfully claims his job is worse than that of Hell’s porter. The porter’s act is a quasi-comedy routine that offers the audience a break from the play’s serious ongoing events. When he opens the door for Macduff and Lennox, the porter continues by engaging them in bawdy jokes. During the time that elapses during the porter’s encounter with Macduff and Lennox, Macbeth washes his hands of King Duncan’s blood. Then Macbeth appears before the guests and directs them to the chamber where, he says, the king “sleeps.” In another instance of dramatic irony, the audience knows the shock that awaits Macduff, who has no idea he will see the murdered king.
As Macduff walks to the king's chamber, Lennox converses with Macbeth. He talks about the previous night's harsh weather: the noises of the birds as well as the tremors of the land. When Lennox comments on the previous night’s tumult, Macbeth agrees. “‘Twas a rough night,” he says.
Macduff interrupts their conversation with a startling announcement. “Our royal master's murdered,” he cries. The subsequent lines depict Macduff’s agony. He uses metaphorical language to avoid explicitly describing the crime. “Murder hath broke ope / The Lord's anointed Temple,” he says, describing the impact of recent developments. He also describes King Duncan’s murder as “the spring, the head, and the fountain of [his] blood is stopp’d.” Whether Macduff knows who killed King Duncan remains is unknown because he fails to point an accusative finger at anyone.
In a bid to conceal his guilt, Macbeth explains that he killed the king’s soldiers when he suspected that they might have been responsible for his death. He says, “Here lay Duncan, / His silver skin laced with his golden blood; / And his gashed stabs looked like a breach in nature / For ruin's wasteful entrance” (113-116). By using vivid imagery in his narration, Macbeth conceals the exact circumstances surrounding the king’s death. His flowery language detracts from his responsibility for the tragedy.
When Lady Macbeth faints in response to Macbeth’s partial confession, it foreshadows future disarray. As soon as Lady Macbeth is lifted off the stage, several events develop that move toward that future. Macbeth and the thanes agree to avenge King Duncan. However, the king’s sons express discomfort with the proceedings. They sense betrayal and feel that they may be targets of future attacks. They see “daggers in men’s smiles” in their current circumstances, and they remain uncertain of whom to trust (141-142).