Judah and Jerusalem are obviously used here as descriptions of Zion generally, of the church generally, because the prophet has only just said, you are going to be cleansed out and there will be remnant, and previously he had said that the Gentiles will come in, and that John the Baptist will come and this will be the time of the gospel. So we know in the light of all that, that he uses the term of Israel and Jerusalem as a general description for the whole church.