What are the main quotes (with line numbers) that develop the theme of ambition in Macbeth?
In Act I, Sc. v Lady Macbeth speaks about Macbeth’s ambition: “...thou wouldst be great;/Art not without ambition, but without/The illness should attend it:...” (I.v.18-20) This important quote enables us to understand Macbeth’s nature which is "too full o' the milk of human kindness...." Lady Macbeth’s provocation enlivens the evil residing in Macbeth and his ambition receives a new dimension: “I have no spur/To prick the sides of my intent, but only/Vaulting ambition, which o'erleaps itself/And falls on the other" (I.vii.25-28).
Later in Act II, Sc. iv Ross considers the hollowness of an ambition, which can destroy a person’s life: “Thriftless ambition, that wilt ravin up/Thine own life's means!” (II.iv.28-29). Undoubtedly, Ross’s comment about "suborn'd:/ Malcolm and Donalbain, the king's two sons" is ironic in nature as, at the end of the play, Macbeth too will lose his life for his own “vaulting ambition.”
Note: The line numbers vary according to editions. The above line numbers are provided according to the Arden edition of Macbeth.
In addition to re-reading the play, you can find quotes at the eNotes link provided below to help you find lines from the play related to ambition. But here are a few to get you started:
Macbeth (after hearing the witches' prophecies for him):
"If chance will have me king, why, chance may crown me/ Without my stir." (Act I, scene iii)
Lady Macbeth (after Macbeth killed Duncan and seems weak from the experience):
"Infirm of purpose!/ Give me the daggers: the sleeping and the dead/ Are but as pictures: 'tis the eye of childhood/ That fears a painted devil." (Act II, scene ii)
Macbeth (trying to prepare himself to kill Duncan):
"I have no spur to prick the sides of my intent, but only/ Vaulting ambition, which o'erleaps itself/And falls on the other...." (Act I, scene vii)
I hesitate giving line numbers as every edition of Macbeth will have different line numbering. It would be best if you looked up the quotes by their act and scene numbers to find where they are located in the edition you are using.
A good quote would be, "Your hand, your tongue: look like the innocent flower,/But be the serpent under't" (1.5). Lady Macbeth says that to Macbeth.
She is trying to say that he should look like he is pure in the eyes of the king and his men. "Look like" a flower is a simile; this tells us that Macbeth should maintain the look of innocence even though he is about to act like a "serpent." This is an allusion to Adam and Eve, the serpent meaning the devil. This shows us that Lady Macbeth is trying to influence him into murdering King Duncan.
So all this shows us that Lady Macbeth is driving her ambition into Macbeth. The Shakespearean audience would of being shocked because, at the time, they were living in a patriarchal society, meaning that men were more dominant than and superior to women.