The evidence from the text which supports the idea that Lady Macbeth questions her husband's ability to kill the king in Act 1 Scene v in "Macbeth" is:
"What thou wouldst highly,
That wouldst thou holily;
wouldst not play false,
And yet wouldst wrongly win."
Explanation:
Lady Macbeth finds her husband to be incapable of killing King Ducan as he was very kind and generous from his heart. She knew it very well that although Macbeth was ambitious he had a soft corner for the King.
