Q. What is the origin of the communal Seder?A. The community Seder is a widespread feature of the observance of Pesach. In Israel thousands of people go away for the festival and the hotels are full of Pesach programs, often commencing with hundreds sharing a Seder in the main banqueting room of the hotel, though some family groups have their own Seder in a room of their own.
The first communal Seder – held before the actual Exodus – was when God told the Israelites to sit around to eat the paschal lamb in groups (Ex. 12:4). By the time of the Mishnah, Pesach had been an annual event for centuries, and part of the celebration must have been group Sedarim, since the rabbis debate whether one may go from one company (chaburah) to another on Seder night.
The Jerusalem Talmud tells us at the end of tractate B’rachot, “One who heard Hallel in the synagogue on Seder night has fulfilled his obligation”. The 14th century liturgical authority David Abudarham explains that this refers to a Babylonian/Spanish custom of running a Seder in the synagogue for the sake of those who were not well versed in the festival procedures.
However, some say that it was not the full Seder that took place in the synagogue, and after the synagogue ceremony people would go home, eat vegetables (karpas), say the blessing “Who has redeemed us” and drink the second cup.
In some places they needed outsiders to conduct the Seder as there were views that everyone present should recite the Haggadah word for word after the leader though only they, but not he, would say the Divine Name in the course of the b’rachot.