Knock within. Wake Duncan with thy knocking, I would thou couldst. In the first line of the quotation, Macbeth is speaking to himself. He means that he would prefer to be totally knocked out, unconscious, so that he would not have to think about the crime he's just committed.
Similarly, it is asked, what does it mean the world is my oyster?
THE WORLD IS AN (ONE'S) OYSTER - "If you have a lot of money, you can have anything you want. The proverb first appears in Shakespeare's play 'The Merry Wives of Windsor' .'Falstaff: I will not lend thee a penny. Pistol: Why, then, the world's mine oyster, Which I with sword will open.' Act II, Scene II."
Why is Macbeth so troubled by the fact that he Cannot say amen?
In William Shakespeare's tragic play Macbeth, Macbeth is unable to say the word "Amen" after murdering Duncan. Macbeth is "caught" by Duncan's servants while in the act of murdering the king. One cried "God bless us!" and "Amen" the other; Therefore, he is able to say the word Amen.