Bassanio meanwhile tries to cheer up Antonio, vowing that he himself shall give Shylock his own life in place of Antonio's "ere [Antonio] shalt loose for me one drop of blood." Antonio, however, is without hope. He tells Bassanio to "live still, and write mine [Antonio's] epitaph."
At that moment, Nerissa enters the courtroom, dressed like a lawyer's clerk, and delivers a letter from Bellario to the duke. While the duke reads the letter, Shylock whets his knife on the sole of his shoe to the horror of Antonio's friends. The clerk of the court then reads aloud the letter from Bellario. The doctor is ill, but he has sent in his place "a young doctor of Rome," named Balthasar, whose wisdom in the law belies his youth. Bellario says that he never knew "so young a body with so old a head," and he asks the duke for his "gracious acceptance" of Balthasar in Bellario's stead.
The duke welcomes young Balthasar, who is, of course, Portia "dressed like a Doctor of Laws." Portia acknowledges that she is familiar with this case and its "strange nature," and she is equally acquainted with the integrity of Venetian law. She asks Antonio if his bond is a valid one, and he admits that it is. She then tells him that Shylock must be merciful. At this, Shylock is shocked: Why should he be merciful? Because, Portia answers, "mercy is . . . [like] the gentle rain from heaven"; mercy is "twice blest; / It blesseth him that gives and him that takes." She continues and says that mercy is an attribute of God. It is freely bestowed to temper justice, and those who grant mercy ennoble themselves, especially those people who have the power to dispense punishment and yet award mercy instead. She points out to Shylock that all people "pray for mercy" and "that same prayer" should teach us all to "render the deeds of mercy."
