This scene further focuses our attention on the use of sheep imagery in connection to money and breeding. Here Shakespeare plays on the words "use", "usury", and "ewes", all of which will be punned throughout the play. All the sheep imagery is on Shylock's side throughout, for he is fleecing the Christians, breeding the ewes. He therefore mentions Jacob as his defense for taking interest, and we can note later that Shylock's wife is named Leah, the same name that Jacob's first wife had. Shylock is also able to make his money breed like sheep through the charging of interest. On the other hand, the Christians have Jason and the Golden Fleece. This image is used in connection with Bassanio, the risk-taker, who risks everything to gain everything. The same image will figure later with Antonio, who is represented as a wether, a castrated sheep. Thus the concept is reinforced that Antonio does not make his money breed because he refuses to charge interest.
Briefly state your position, state why the problem you are working on is important, and indicate the important questions that need to be answered; this is your "Introduction." Push quickly through this draft--don't worry about spelling, don't search for exactly the right word, don't hassle yourself with grammar, don't worry overmuch about sequence--that's why this is called a "rough draft." Deal with these during your revisions. The point of a rough draft is to get your ideas on paper. Once they are there, you can deal with the superficial (though very important) problems.