How does Shylock "raise the stakes" on the terms of the loan to Antonio?

Shylock "raise the stakes" proposing that Antonio repay the loan with his own meat from his body, if he cannot pay with money within the given time.

Explanation:

Shylock is a Jewish moneylender who was once very humiliated by Antonio who was extremely anti-Semitic and anti-Jewish. Shylock had a very bad grudge towards Antonio and when he needed a loan of money to make a certain trip, Shylock did not hesitate to propose the loan of a high amount that should be paid in a short time, besides he "raised the stakes" , stating that the loan would have Antonio's meat as interest if the payment was not made as agreed. Shylock said that if Antonio did not pay correctly, he would have to pay off the debt with a pound of meat from his own body.