Bikkurim, Chapter Three, Mishnah Two
Our mishnah begins to describe the ceremony of bringing the bikkurim to the Temple. While a person could bring his bikkurim to the Temple on his own, the mishnah prefers to describe a festive ceremony in which everyone from all of Israel would bring their bikkurim at the same time.
1) How were the bikkurim taken up [to Jerusalem]? All [the inhabitants of] the cities of the maamad would assemble in the city of the maamad, and they would spend the night in the open street and they would not entering any of the houses.
2) Early in the morning the officer would say: Let us arise and go up to Zion, into the house of the Lord our God (Jeremiah 31:5).
In Temple times the priests were divided into 24 mishmarot. The main purpose of this division was that each week a different mishmar of priests would serve in the Temple. Parallel to the division of the priests, the other people were divided into maamadot. When a mishmars priests were serving in the Temple, the people of the corresponding maamad would gather in the synagogues and read from the beginning of the book of Genesis. Others from the maamad would go up to Jerusalem with the priests to serve as their regions representatives when the Tamid daily sacrifice was being offered in the Temple. One person was designated the Rosh Hamaamad or the Head of the Maamad, and it was in his town that the people would gather. For more on this topic see Taanit 4:2.
When it came time to bring bikkurim up to the Temple, all of the people of the various cities of the maamad would gather together in the city of the maamad which was the city where the Rosh Hamaamad dwelled. They would not sleep inside, but rather outside in the street. This would prevent them from possibly contracting corpse impurity inside the houses. Corpse impurity would disqualify them from bringing the bikkurim.
When they rose in the morning, an appointed officer would begin the ritual by reciting a charge taken from the book of Jeremiah.