How does lady macbeth influence macbeths decision to murder duncan

Lady Macbeth arrives and tells her significant other that the king has dined and that he has been requesting for Macbeth. Macbeth proclaims that he no longer plans to kill Duncan. Lady Macbeth, infuriated, calls him a coward and questions his manhood: "When you durst do it," she says, "then you were a man" (1.7.49).