In order to understand this particular section of this scene, when Shylock talks to Jessica, it is important to be aware of the context of the scene as a whole. Launcelot has been sent by his new master, Bassanio , to tell Shylock that his presence is expected at...
In order to understand this particular section of this scene, when Shylock talks to Jessica, it is important to be aware of the context of the scene as a whole. Launcelot has been sent by his new master, Bassanio, to tell Shylock that his presence is expected at the feast to which Shylock has been invited. Remember however that Launcelot has just left working for Shylock as a servant to work for Bassanio as his new servant. In addition, he has been sent by Lorenzo to tell Jessica that Lorenzo will elope with her that evening whilst her father is away having dinner with Bassanio. Launcelot has just managed to pass on this information to Jessica, before he leaves. However, Shylock notices that he has been able to say something to Jessica and immediately wants to know what he said. When Jessica says that Launcelot bid her nothing except farewell, Shylock then talks about Launcelot, using language that emphasises Launcelot's laziness and how unprofitable he is:
The patch is kind enough, but a huge feeder;
Snail-slow in profit, and he sleeps by day
More than the wild-cat: drones hive not with me;
Therefore I part with him, and part with him
To one that would have him help to waste
His borrow'd purse.
The "patch" in this quote refers to Launcelot, who, in Shylock's opinion, may be "kind enough," but the problem with him is that he eats a lot, in as slow as a snail in getting his work done (so Shylock does note "profit" from his service) and sleeps all day. Note that he is compared to various animals with unsavoury qualities. In the expression "drones hive not with me," Shylock uses an implicit metaphor to compare Launcelot to a drone, a bee that does not work and has no industry or diligence. He makes it clear that to work in Shylock's home, a servant must be useful, not a sleeping, eating sluggard. Therefore, because Launcelot is incompetent, Shylock is happy for him to go to Bassanio, since Launcelot, with his unproductive ways, will "help him waste / His borrow'd purse." Bassanio's purse is "borrow'd" precisely because it is money that has just been acquired from Shylock. There is an irony here: Shylock is happy to lose Launcelot on two counts as he is useless and also he will help Bassanio continue in his wasteful ways with the money his new master has just gained from Shylock, indirectly helping Shylock's business of usury. Note the language emphasises Shylock's focus on profitability and money. One interpretation is that the various animal comparisons present Shylock as looking at other humans not so much as people in their own right, but only as consumers and producers of money, therefore effectively dehumanising them.