“They made a proclamation throughout Judah and Jerusalem to all the returned exiles that they should assemble at Jerusalem. If anyone did not come within three days, by order of the officials and the elders, all their property should be forfeited. They themselves would be banned from the congregation of the exiles. Then all the people of Judah and Benjamin assembled at Jerusalem within the three days. It was the ninth month, on the twentieth day of the month. All the people sat in the open square before the house of God, trembling because of this matter and because of the heavy rain.”
Somehow these people in Jerusalem had the authority to issue a proclamation demanding that everyone in Judah and Jerusalem had to come for this great assembly in Jerusalem. For the people in Jerusalem this was no problem. However, if the others from Judah did not come their property would be confiscated and they would be banned from the exiled group. There is no mention of any other Israelites. This was strictly a Judah move. They all gathered on 9/20 of that year. They were trembling in the open square before the Temple because of this matter, plus the rain since this apparently was the rainy season.