What were the requirements to be a member of the Sanhedrin?
According to the context, a person could not be a member of the Sanhedrin unless they were married and had children. The stated purpose was that one cannot judge in areas of family relationships without having had that experience.
Les explains that the ruling body of Jews was the Sanhedrin. He maintains that, under the Jewish Old Testament economy, a man could not be a member of the Sanhedrin unless he was married and had children. The purpose was that a person cannot judge in the areas of family relationships if he has never had that experience. Les then connects this same premise to I Timothy chapter 3, where Paul carries it into the leadership of the Church, asking how leaders can lead intelligently and from experience if they have never had the responsibility of being a husband and a father.