The animosity between Antonio (a Christian) and Shylock (a Jew), though they both lend money, is the primary conflict in WIlliam Shakespeare's The Merchant of Venice. The two men have a longstanding and mostly religious hatred of one another, but it is intensified in Act I scene iii of the play, when Antonio's friend Bassanio needs to borrow some money and Antonio is temporarily without the means to loan him any.
Bassanio goes to Shylock, and Shylock agrees to lend Bassanio three thousand ducats for three months--without interest but in exchange for a pound of Antonio's flesh if the loan is not repaid.
In the lines you cite, Bassanio is horrified at the arrangement and does not want to finalize the deal; Antonio, however, is not in the least concerned. He says:
Why, fear not, man; I will not forfeit it:
Within these two months, that's a month before
This bond expires, I do expect return
Of thrice three times the value of this bond.
Antonio is not at all worried about having to pay the penalty, since he is expecting a great profit (three times the amount of the loan) to come from his current business venture. Shylock's immediate response is this:
O father Abram, what these Christians are,
Whose own hard dealings teaches them suspect
The thoughts of others! 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 favour, I extend this friendship:
If he will take it, so; if not, adieu;
And, for my love, I pray you wrong me not.
Shylock again insults Christians, who are supposed to be loving and kind, for thinking the worst of him. He downplays the payment he wants as a forfeit, remarking that a pound of human flesh is not nearly as valuable as the flesh of animals which men eat. Shylock says he offers this deal in friendship (hah!) and Bassanio and Antonio can accept it or not. He just hopes that Antonio will not mistreat him for his kindness and generosity.