O Jerusalem, Jerusalem, the city that kills the prophets and stones those who are sent to it! How often would I have gathered your children together as a hen gathers her brood under her wings, and you would not!
This has often been a verse used to argue against a Calvinistic understanding of limited atonement and reprobation. Jesus here seems to be saying that he wanted to gather these men to themselves though they, through their own disobedience, rejected his offer.
Unfortunately, this argument has been weakened by Dave Hunt and the like. Arminians have often misquoted this verse saying, "how often I would have gathered you together". This would change the meaning of the verse so that Jesus is telling those whom he is speaking to that he wanted to gather them together.
However, despite this verse being often misquoted, I still think it can be used to argue for a universal saving will in God. Jesus is here talking to the leaders of Jerusalem rather than Jerusalem itself. He is saying that he wanted to gather the people of Jerusalem together, but their corrupt leaders would not allow him.
James White and others have argued that because Jesus is talking to the leaders rather than the people of Jerusalem themselves, this verse cannot be used to support a universal saving will in God. I, however, disagree. The fact still remains that Christ wept because these people were not saved, and longed for them to be saved. The fact that he is talking to their leaders rather than the people themselves makes no difference.
There is a clear instance in this verse of Christ stating that he longed to save those who were not saved, and even wept at their lack of salvation. Though God has from eternity elected specific men unto salvation, he has a will to truly offer salvation to all.