Methought I heard a voice cry "Sleep no more; Macbeth does murder sleep."
Why worthy thane, you do unbend your noble strength.
Lady Macbeth has gotten King Duncan's servants drunk and had a little herself for courage.
Knock, knock, knock...
Get on your nightgown, lest occasion calls us, and show us to be watchers.
Macbeth tells Lady Macbeth that he has killed King Duncan.
Will all great Neptune's ocean wash this bloodClean from my hand? No, this my hand will rather The multitudinous seas incarnadine,Making the green one red.II.ii.59-62
Give me the daggers.
Macbeth is feeling guilty about what he's done, but Lady Macbeth questions why he's acting so weak and says that thinking like this will drive them both crazy.
Lady Macbeth takes the daggers to plant on the servants when someone starts knocking on the door. She tells Macbeth to put his pajamas on so that no one will know they were already up, while he wishes that the knocking could wake up Duncan.
Wake Duncan with thou knocking, I would thou couldst.
Literary Device: When Macbeth says this, he is using exaggeration because, of course an ocean would wash the actual blood off his hands, but it wouldn't wash clean his conscience.