"The Mediator" is Moses, who, having learned and embodied God's Commandments, proclaimed them to the nations, guided them in their fulfillment, showed them God's "Way" by which they should walk to attain righteousness, and so became the "Mediator" between God and the people.

"Mediator" is also Jesus Christ, who, like Moses, having perfectly realized and embodied God's Commandments, in His Teachings and holy way of life revealed, revealed to the peoples the spiritual "Image" and "Likeness" of God, and so became the One Mediator between God and people.

All true Messengers of God, His representatives, pious people - Patriarchs, Prophets, Christ, Apostles - were also "Mediators" in the realization of Divine, "Heavenly" principles on earth, in the figurative sense.