Minyan: The Congregational Quorum
Only in a group of ten or more is there sufficient sanctity to recite certain public prayers.
Rabbi Millgram wrote before it became the prevailing (but not universal) custom, as it is now, for women to be included among those whose presence constitutes a minyan in non-Orthodox synagogues. Reprinted with permission from Jewish Worship, published by the Jewish Publication Society.
Congregational worship [has traditionally been] preferred to private devotions because it enabled one to respond to the reader's call to worship ["Bar'khu"] and to recite the Kedushah [the expanded third blessing during the reader's repetition] of the [Amidah, or "Shmoneh Esreh"--the common core of every prayer service]. At a public service one could also hear the reading of the scriptural selections, and a mourner could recite the Kaddish. In addition, one experienced the interstimulation that comes from worship with coreligionists.
What constitutes a congregation? The answer is a minyan, a minimum of ten adult Jews (an adult Jew is any Jewish male who has passed his thirteenth birthday). The number ten was derived from the first verse of Psalm 82, which reads: "God stands in the congregation of God." The word edah (congregation) is also applied to the ten spies who, in the days of Moses, rendered a negative report on the land of Canaan. Hence it was established that a "congregation of God" consists of at least ten men.
In the geonic period the definition of the minyan was not rigid. In Massekhet Soferim (10:8), a late geonic work, we read that a minyan is required for the recitation of certain prayers--but, it is added, "our Sages in Palestine recite these prayers in the presence of seven . . . and some say even in the presence of only six." The practice of the Palestinians did not prevail, however. The rule of the Babylonian Jews was adopted everywhere, and a full quorum of ten men has been required for public prayer.
It has also been argued whether one may include in the minyan a boy under thirteen when only one person is lacking for the quorum.
The authorities never agreed in this respect. Whilst the one insisted upon [the boy's] having obtained his majority, the other was satisfied with his showing such signs of intelligence as would enable him to participate in the ceremony in question.
While the authorities have disagreed, congregational practice has usually been uncompromising. A congregation to be hallowed by the divine presence and to deserve the official designation of kehillah kedoshah (holy congregation) had to have the required quorum of ten mature worshipers.
The rabbis assumed that a minyan was not a hardship on any community. Larger communities were obviously not affected by this requirement, since they always had at least ten men of leisure known as batlanim. These men constituted the core of the permanent congregation and were highly respected for their piety and learning. In later centuries these men became paid functionaries and were frequently regarded as the ne'er-do-wells, who received a dole from the community in the form of a payment for their availability at all times for a congregational quorum.