If I can catch him once upon the hip,
I will feed fat the ancient grudge I bear him. (I.iii.46-47)
In an aside during the third scene of the play when Bassanio and Antonio approach Shylock for the loan, Shylock describes the reasons he hates Antonio, ending with this description of revenge. His use of “ancient” references a history of anti-Semitism in Europe much older than him and Antonio, and “feed fat” is an example of the base, animal language that characterizes Shylock as gruesome and monstrous. This aside sets up Shylock’s main motivation for the play, which is revenge on Antonio as a symbol for revenge on a society that has wronged him and his ancestors.
The villainy you teach me I will execute, and it shall go hard but I will better the instruction. (III.i.70-73)
In the final line of Shylock’s famous “hath not a Jew eyes?” speech, Shylock describes nature of revenge as a never-ending and intensifying cycle. He demonstrates that he understands that killing Antonio would be a larger crime than Antonio’s offenses against him, but prefers it that way. In this line Shylock simultaneously validates his desire for revenge, explaining that he’s only a villain because Antonio and his friends have taught him to be that way through their cruelty, and condemns it, explaining how he would take pleasure in a greater punishment for Antonio.
Thou shalt have more justice than thou desir’st (IV.i.330)
Just before Portia, disguised as Balthazar during the trial scene, delivers her verdict, she tells Shylock that he will have more justice than he wants. The phrase “more justice” stands in for punishment. This line sets us Portia’s verdict as Shylock’s punishment for trying to collect the terms of his loan, or revenge for trying to kill Antonio. Portia, like Shylock, acts out of a desire for revenge against those who threaten her tribe, showing that the attitude permeates the play.