Answer:
Lady Macbeth mentions these words in Act 1, Scene 5.
In this scene, she is recommending her husband Macbeth about the correct way to act when they receive the visit of king Duncan and his men.
Specifically, she wants her husband to do is seem like a welcoming host when the King arrives, because this would be the only way for him to hide his true intentions, that is, to commit murden on the King and usurpt the throne.
Explanation:
She tells Macbeth to appear welcoming and innocent as a flower by controlling how he looks, how he moves and how he talks.
Hope this helps!
