Bring forth men-children only,
For thy undaunted mettle should compose
Nothing but males.
Most of the interactions between Lady Macbeth and Macbeth see Lady Macbeth scolding and egging on Macbeth, attacking his sense of manliness so she can get him to behave in a certain way. This scene is no different - prior to this quote, she had been accusing Macbeth of being weak and soft, since he was beginning to doubt the whole murder scheme. However, when Lady Macbeth exposes the plan of how to efficiently execute Duncan, she expresses it with so much conviction and passion, all the while basically daring Macbeth to live with conviction, to the point where Macbeth gets taken aback and is forced to change his opinion.
Sexuality & Gender: Lady Macbeth’s most scary attribute is her ability to toss away any shred of femininity that a Shakespearean audience would have expected from a woman. This willful tossing away such a fundamental part of her identity would have also been seen as unnatural, relating to the theme of natural vs. unnatural.