Antonio believes that his ships will return safely and he will have no problem paying off his bond. However, this certainty is in direct conflict with everything the audience has heard so far about Antonio's ships and investments. Antonio is over confident about the security of his investments; this foreshadows that this cockiness will end badly for him.
Shylock highlights the uncertainty of Antonio's wealth. Sailing at the time was extremely hazardous because of natural disasters, poorly made vessels, and human frailty. This list of potential disasters foreshadows the main conflict in the play and shows Antonio's imprudence in taking this bond before he knows how his ships will fair.
By this Launcelot means trick your father. Jessica is Shylock's daughter and Jewish, therefore, she would not be allowed to marry a Christian. Any Christian man would either have to trick Shylock, or Jessica would have to secretly convert. This foreshadows what will happen in the play.
"drones hive not ..."See in text(Act II - Scene V)
Drones are male bees within a hive that do no work for the hive. Shylock refers to Launcelot with this series of metaphors to show that Launcelot was lazy and easily replaceable. What Shylock does not seem to realize is that he is losing Jessica as he is losing Launcelot.
" keep his day..."See in text(Act II - Scene VIII)
By this Solanio means Antonio must be able to pay off his debt to Shylock by its due date or Shylock will exact his revenge by brutally collecting his debt. This worry foreshadows the end of the play and offers a reason for Shylock's behavior later in the play.
"I stand here for law...."See in text(Act IV - Scene I)
Shylock has complete confidence that in standing by the law his means will be protected. Ironically this confidence will be his downfall. He ignores the spirit of the law and instead relies on a literal interpretation of the words, which foreshadows how the court will subvert the fulfillment of his bond.
By this Portia means much or a lot of swearing that becomes meaningless in its repetition. The rings have become symbolic for the bond between two people. In giving the "rings away to men," Portia and Nerissa's husbands have symbolically made the bond between two men more important than the bond between them and their wives. Portia and Nerissa must now use the rings to assert power over their husbands.
