Lady Macbeth tells her husband to "look like the innocent flower/But be the serpent under it". Explain what she means.

Essentially, Ladyis urging her husband to put
on an act. To help advance his ruthless ambition he should give the impression of being
completely gracious and charming, friendly and reasonable, whenarrives that evening. Yet at the
same time he shouldn't lose sight of their plan to have him killed.

Ladyis
highly adept at the skill of dissimulation, or hiding one's true thoughts or feelings. And as
she's insanely ambitious for Macbeth, she wants to pass on this vital political skill to someone
for whom it doesn't come quite so naturally. In fact,tells her husband bluntly how easy it is
for other people to read his facial expressions:

"Your face, my thane, is as a book where men

May read
strange matters. To beguile the time,

Look like the time. Bear welcome in
your eye,

Your hand, your tongue." (act 1 scene 5)

Macbeth must try to appear the way that other people expect him
to appear. After all, Duncan is the king, even though Macbeth plans to kill him, so he should be
formally treated as such upon his arrival. This will help lull him into a false sense of
security, making it easier for Lady Macbeth's dastardly plot to be successfully carried
out.