Now the angel of Yahweh spoke about the problems of Jerusalem and Judah. Why had Yahweh been angry at these places for 70 years? This was approximately the time between the destruction of Jerusalem in 587 BCE and then 520 BCE. However, Yahweh replied to the angel with gracious and comforting words. Then the angel of Yahweh turned to Zechariah. He told him to proclaim a message that Yahweh of hosts was jealous about Jerusalem and Zion. They were not going to be abandoned.
Jeremiah was obviously sent to Jerusalem and the towns of Judah with their kings and officials. There is no mention of how many towns in Judah, but usually that is a euphemism for its leaders. They were going to be laid waste like a desolation. They would become the object of hissing and cursing just as they are today. This seems to imply that the exile was actually taking place at this time.