You may think that ten people constituting a minyan derives from Abraham’s bargaining God down to ten good people in Sodom and Gomorrah. If you think that, you are mistaken. Ten people constituting a minyan derives from this week’s Torah portion, Shelach Lecha. The Talmud tells us so. Follow the logic.
The Talmud states, ten people are needed for community prayers (Kadish, Kedushah, Barchu), and asks, where is the principal derived? Leviticus 22:32 says, “And I shall be hallowed among the children of Israel.” which indicates that any expression of sanctity may not be recited in a quorum of fewer than ten. How many people? Follow the logic.
The sages stated a few hermeneutical rules to interpret the Torah. (If you don’t know “hermeneutical,” the definition hermeneutical is, “the branch of knowledge that deals with interpretation, especially of the Bible.”) One of the rules is gezeira shava: two verses in the Torah (very far apart) contain the same word. The same identical word is interpreted the same way.
The operative word is “among.” One verse, Leviticus 22:32 says, “And I shall be hallowed among the children of Israel.” A different verse, Numbers 16:21 (Korach), says, “Separate yourselves from among this congregation.” As of now, we don’t know how many people can constitute a minyan.
The number ten derives from another gezeira shava. The operative word is “congregation.” Numbers 16:21 says, “Separate yourselves from among this congregation [i.e., separate from Korach’s followers].” In this week’s Torah portion Moses says, “How long shall I bear with this evil congregation?” “Congregation” refers to the ten spies who reported negatively. The Kadish, Kedushah, and the Barchu are expressions of sanctity, and they consequently require a quorum of ten.