'Mediator' in the Bible

If there is an angel beside him, one mediator out of a thousand, to tell a person what constitutes his uprightness;

"I, the Lord, officially commission you; I take hold of your hand. I protect you and make you a covenant mediator for people, and a light to the nations,

This is what the Lord says: "At the time I decide to show my favor, I will respond to you; in the day of deliverance I will help you; I will protect you and make you a covenant mediator for people, to rebuild the land and to reassign the desolate property.