Macbeth says "this is a sorry sight", looking at his bloody hands moments after he has murdered King Duncan. His wife thinks that's a stupid thing to say, and when she notices that he has brought the bloody daggers from King Duncan's room, she thinks he's even more stupid. She tells him that he must take the daggers back, place them with the King's sleeping guards, and cover them with the King's blood. Macbeth, however, is so shaken that all he can do is stand and stare at his bloody hands, so Lady Macbeth takes the daggers from him. When she goes to do the job she thinks he should do, Macbeth still stands and stares. He asks himself if all the water in the world can wash away the blood "will all great Neptune's ocean wash this blood clean from my hand?" and he answers his own question, "no, this my hand will rather the multitudinous seas incarnadine, making the green one red."
His wife thinks his obsession with blood shows that he's a coward. She dips her hands in the dead King's blood, and covers the guards with the blood, then tells Macbeth that "my hands are of your color; but I shame to wear a heart so white." She means that now her hands are bloody, like his, but she would be ashamed to have a bloodless and cowardly heart like his. She leads him away to wash his hands, and she seems quite sure that a little water clears them of the deed they have done. Ironically, when she later goes mad, she sees blood on her hands that she cannot wash away, no matter how much water she uses.
Telling Malcolm and Donalbrain of their father's murder, Macbeth says "the spring, the head, the fountain of your blood is stopped; the very source of it is stopped." Here, the primary meaning of "your blood" is "your family," but Macbeth's metaphors also picture blood as a life giving essence. A second later, blood is spoken of as a sign of guilt. Lennox says that it appears that the King was murdered by his body guards, because they were covered in blood. In another second, blood appears as the precious clothing of a precious body, when Macbeth, justifying his killing of the guards, describes the King's dead body as "here lay Duncan, his silver skin laced with his golden blood." Then Donalbain says to his brother "the near in blood, the nearer bloody," meaning that as the murdered King's sons, they are likely to be murdered themselves.
It's strangely dark on the morning after the night of King Duncan's murder, and Ross says to an old man "ah, good father, thou seest, the heavens, as troubled with man's act, threaten his bloody stage." The "stage" is this earth, where we humans play out our lives. Because of Duncan's murder, the stage is bloody and the heavens are angry. Moments later, Macduff enters and Ross asks him "is't known who did this more than bloody deed?" The deed is more than bloody because it is unnatural. The King Duncan was a good and kind man whose life naturally should have been cherished by everyone.
Macbeth appears as King of Scotland mentions to Banquo in a seemingly casual way that Malcolm and Donalbain, "our bloody cousins," are in England and Ireland where they are denying that they killed their father. By referring to them as "bloody", Macbeth wants to emphasize their guilt. After Banquo...