70 elders – B’ha’alot’cha
The sidra (Num. 11:16) reports God’s command to Moses to appoint seventy elders as an advisory and judicial council.
Yet in Num. 16:2 there is a reference to 250 leaders, so what are we talking about here?
Possibly there was a council of 250 and an inner executive of 70.
Calling them elders does not necessarily indicate chronological age but wisdom and experience. In that sense one can be old in years but young in mind, or alternatively young in years but old in wisdom.
According to the rabbis, zaken (“old”) suggests zeh kanah chochmah, “a person who has acquired wisdom” (commentaries on Lev. 19:32). The halachah asks whether Moses himself was one of the seventy, or was an additional person, making a total of seventy-one.
The halachic principle is that there was a court of seventy-one judges, part of a system in which all courts had an odd number of judges, which ensured that there could never be a deadlock but there was always a majority and a minority.