"eye doth teach;..."See in text(Act II - Scene IX)
Here, Arragon touches on the lesson presented in the previous scene with Morocco: one should never judge something by its exterior appearance. This statement is ironic however, because Arragon just dismissed the iron chest because of its appearance.
Notice that Bassanio can only focus on Portia's external beauty as he looks at her portrait. This is ironic given that he has just extolled external appearances as false and shallow.
" outward parts...."See in text(Act III - Scene II)
Ironically, Bassanio catalogues all of the people who deceptively look different than what they actually are when he himself has borrowed money in order to look richer than he actually is. This suggests that Bassanio may not have passed the casket test without Portia's guidance. The test is designed to deter suitors who are there for the gold, and from the beginning of the play, the audience knows that Bassanio is this kind of suitor.
In mythology, Alcides, or Hercules, saved Hesione, the princess of Troy, from a sea monster sent by Poseidon to punish Hesione's father for breaking a bond. Hesione was stripped naked and tied to a rock to await the monster when Hercules came across her. He promised her father to rescue her in exchange for a herd of magical horses. Portia compares Bassanio to Hercules and herself to Hesione. She claims that Bassanio intends to rescue her because he loves her instead of for monetary. However, this metaphor is slightly ironic as Bassanio could, like Hercules, intend to rescue Portia for the reward.
"lover of my lord ..."See in text(Act III - Scene IV)
Notice that Lorenzo's words are both a sincere statement of Antonio's good character and a hint at the nature of Bassanio and Antonio's relationship. This speech emphasizes a theme of careless speech in the play: characters often speak without recognizing what their words imply.
"An if your wife be not a mad woman,
..."See in text(Act IV - Scene I)
Shakespeare uses dramatic irony here for comedic effect. The audience knows that this doctor is actually the person as this "mad wife." While the doctor claims that only a mad woman would be upset about giving a ring to the man who saved Bassanio's best friend, Portia is actually testing Bassanio's fidelity. She will be angry if he gives away the ring.
"behind her back;..."See in text(Act IV - Scene I)
Again, Gratiano offers his wife's life for Antonio's thinking that Nerissa cannot hear him. Ironically, he does not say this behind her back but to her face.
Portia invokes dramatic irony with this statement, because Bassanio's wife is in fact "by to hear him make the offer." Bassanio's confession of love makes it all the more urgent that Portia save Antonio and rid Bassanio of his bond to his friend. She must redirect this love towards herself.
Notice that within her speech about divine mercy and forgiveness, Portia still refers to Shylock as "Jew" rather than by name. This is a sign of disrespect. Portia sees Shylock as a label rather than as a person. There is no understanding, forgiveness, or mercy towards Shylock within this speech; ironically, it is a speech about empathy that is devoid of actual empathy.
"How shalt thou hope for mercy, rendering none?
..."See in text(Act IV - Scene I)
Again the Duke asks Shylock to be better than the Christians in the play. In this question, the Duke inadvertently claims that Shylock must first show mercy before he can be shown mercy. This is ironic because mercy is a cornerstone of the Christian faith, yet none of the Christians showed Shylock mercy earlier in the play.
" a gentle answer..."See in text(Act IV - Scene I)
Gentle puns on the word "gentile," another word for Christians. The Duke narrates what Shylock should do, then ends the speech essentially asking Shylock to imitate the Christians. However, remember that earlier in the play Shylock declared that his adamant desire for revenge was taken from Christian example. Ironically, in attempting to exact revenge, Shylock is imitating the Christians.
Ironically, Portia does know to whom Bassanio gave the ring, for what purpose, and in what manner. While Bassanio claims that if she knew these things she would readily forgive him, it is actually for these very things that she does not forgive him. In repeating this phrase, Bassanio add to the tension and comedy of the scene.
"What ring gave you my lord?
Not that, I hope, which you receiv'd of me...."See in text(Act V)
Shakespeare uses dramatic irony here to build tension and comedy. Portia and the audience know that Bassanio has given her ring away to the doctor (who was Portia herself). In feigning ignorance to what happened, Portia is able to present herself as an innocent victim and hyperbolize her disappointment.
Lorenzo and Jessica recount these famous stories of lovers in anticipation in order to classify their love as one of the great love stories in history. This catalogue of tragic lovers is ironically comedic however, because each of the love stories they mention ends tragically with the lovers betraying each other or dying.
