How we cite our quotes: (Act.Scene.Line). Line numbers correspond to the Norton Shakespeare edition.
Quote #1
SHYLOCK
Signior Antonio, many a time and oft
In the Rialto you have rated me
About my moneys and my usances.
Still have I borne it with a patient shrug
(For suff'rance is the badge of all our tribe).
You call me misbeliever, cutthroat dog,
And spet upon my Jewish gaberdine,
And all for use of that which is mine own.
Well then, it now appears you need my help.
Go to, then. You come to me, and you say
"Shylock, we would have moneys"—you say so,
You that did void your rheum upon my beard,
And foot me as you spurn a stranger cur
Over your threshold. Moneys is your suit.
What should I say to you? Should I not say
"Hath a dog money? Is it possible
A cur can lend three thousand ducats?" Or
Shall I bend low and, in a bondman's key,
With bated breath and whisp'ring humbleness,
Say this:
"Fair sir, you spet on me on Wednesday
last;
You spurned me such a day; another time
You call'd me 'dog'; and for these courtesies
I'll lend you thus much moneys"? (1.3.116-139)
Shylock makes the reasonable point that it would be questionable if he were simply to repay Antonio's injustices against him with kindness. This would be merciful, but Antonio doesn't ask him for mercy, nor does Shylock seem too keen to give it. Their hatred of each other may have been justified, but when Antonio comes to seek help from Shylock, the tables are turned. Shylock can rightfully demand an apology, or at least some recognition of the injustice against him.
Quote #2
ANTONIO
If thou wilt lend this money, lend it not
As to thy friends, for when did friendship take
A breed for barren metal of his friend?
But lend it rather to thine enemy,
Who, if he break, thou mayst with better face
Exact the penalty. (1.3.142-147)
Antonio is really asking for it here. He says that because he's not coming to ask for money out of friendship, and this is just business, Shylock has the right to exact a penalty should Antonio fail his bond. While Shylock's seeking a pound of flesh seems rather extreme, it can be linked back to Antonio's extravagant and unapologetic manner of asking for the money in the first place.
Quote #3
SHYLOCK
Pray you, tell me this:
If he should break his day, what should I gain
By the exaction of the forfeiture?
A pound of man's flesh taken from a man
Is not so estimable, profitable neither,
As flesh of muttons, beefs, or goats. I say,
To buy his favor, I extend this friendship.
If he will take it, so. If not, adieu;
And, for my love I pray you wrong me not. (1.3.174-182)
We've got to wonder why Shylock actually does want Antonio's flesh. It's suspicious that he had the pound-of-flesh solution in mind, and even more suspicious that he defends it so glibly as no big deal. Maybe Shylock was never kidding about the pound-of-flesh thing, and it was all premeditated.