Genesis 18 in the context of "Naso (parsha)"

In Judaism, a minyan (Hebrew: מניין \ מִנְיָן mīnyān [minˈjan], lit. (noun) count, number; pl. מניינים \ מִנְיָנִים‎ mīnyānīm [minjaˈnim]) is the quorum of ten Jewish adults required for certain religious obligations. In all traditional orthodox practising Jewish religious movements, only men aged 13 years and older may constitute a minyan. The minimum of 10 Jews needed for a minyan has its origin (in part) in Abraham's prayer to God in Genesis 18:32. The minyan has additional roots in the judicial structure of ancient Israel as Moses first established it in Exodus 18:25 (i.e., the "rule of the 10s"). Cyrus Adler's and Lewis Naphtali Dembitz's entry for "Minyan" in the Jewish Encyclopedia states: "The minimum of ten is evidently a survival in the Synagogue from the much older institution in which ten heads of families made up the smallest political subdivision. In Ex. xviii. Moses, on the advice of Jethro, appoints chiefs of tens, as well as chiefs of fifties, of hundreds, and of thousands. In like manner there were the decurio among the Romans and the tithingman among the early English."

The most common activity requiring a minyan is public prayer. Accordingly, the term minyan in contemporary Judaism has taken on the secondary meaning of referring to a given prayer service, in general.