Without relating the quote to Macbeth, it its already obvious that it is talking about a king or queen beacause it mentions a crown. This quote focuses on the darker meaning of the position of a king. To be a king you can't be some pushover that listens to the people, you have to play unfair. You have to go against the people, be cruel.
According to Lady Macbeth the postition of a King isnt for a baby. It must be taken.
At this point in the story the three witches each call Macbeth by a different name. One calls him the Thane of Cawdor, another calls him Thane of Glamis, and the last one calls him a king. Macbeth knew of his currerent position as a thane, but he did not know that he was going to be promoted to king. Macbeth is excited with the news, but Lady Macbeth thinks that he isn't a good fit for king. Lady Macbeth is willing to do almost anything to make Macbeth king, even kill. However, he doesnt share the same cruel drive that she has. But her persistance gets in his head. After much conversation Lady Macbeth has Macbeth willing to do anything to be king, even if that means not playing by the rules.
