Though that nature with a beauteous wall / Doth oft close in pollution (1.2.)
Viola praises the Captain’s kind and honorable behavior toward her. She notes that people may sometimes be physically attractive but not honorable on the inside. However, she believes that the captain is both handsome and good. The quote is significant because it touches on the theme of appearance versus reality, which will be important for the remainder of the play.
Whoe’er I woo, myself would be his wife (1.4.)
Viola reflects on the uncomfortable position she finds herself is. While in disguise, she has been charged with wooing Olivia on behalf of Orsino, but by now Viola is in love with Orsino herself. The line is the first time Viola speaks about her attraction to Orsino, and it reveals to the audience that, by disguising herself, she has put herself in a challenging and precarious situation.
Lady, you are the cruel’st she alive / If you will lead these graces to the grave / And leave the world no copy (1.5.)
Viola rebukes Olivia for rejecting Orsino, and for insisting on remaining single. Viola says that since Olivia is so beautiful, it would be a shame for her to remain single (and thus, presumably childless). If Olivia never has children, her beauty will die with her, which Viola thinks would be a shame. The quote is important because Viola is actually speaking to Olivia as another woman, and thus her advice about getting married and having children takes on a different tone.
Disguise, I see thou art a wickedness (2.2.)
Viola is alarmed that Olivia, thinking Viola is Cesario, has fallen in love with her. Although Viola initially thought being disguised as a man would make her life easier and help keep her safe, she realizes that the disguise also creates problems for her. In Shakespeare’s original context, the quote would likely have comic implications for the audience, since Viola would have been portrayed by a young man dressed as a woman.
O time, thou must untangle this, not I (2.2.)
Viola laments the difficult situation she finds herself in. Because she does not want to reveal her true identity and history, there is little she can do to fix all the confusion, or correct the situation. She simply has to sit back and wait, and hope that things work themselves out. The line foreshadows the way that fate and coincidence will end up resolving the conflict of the play without much direct intervention from the characters.
My father had a daughter loved a man / As it might be, perhaps, were I a woman / I should your lordship (2.4.)
Viola hints to Orsino about her true feelings for him. Orsino does not pick up on the clues because he believes Viola is a man, and that the two of them are speaking man to man. Orsino assumes Viola is talking about a sister but the audience knows Viola is really speaking about herself. However, even by disguising her comment with reference to a woman, Viola comes very close here to admitting her love for Orsino, and therefore the quote has potential homoerotic connotations in that a man seems to be hinting at his love for another man.
Oh, if it prove / Tempests are kind and salt waves fresh in love (3.4.)
Viola starts to hope that Sebastian has in fact survived the shipwreck. News about a man who looks just like her makes her wonder if Sebastian could still be alive. Viola reflects that the ocean, which she had previously thought of as cruel and dangerous, might actually have been benevolent in sparing both her and her brother. The quote is important because it shows Viola starting to see a connection to her past life and hope that she might be reunited with her family.