Ok, bear with me here please
I wanted to get more into the Biblical usage of the word “Mediator” being prompted to do so by I Timothy 2:5. This thread is not about praying to saints though. This is about the “mediator” of the Old Testament/Covenant/Law.
Ok, Galatians 3:19,20
Why the Law then? It was added because of transgressions, having been* ordained through angels by the agency of a mediator**, until the seed should come to whom the promise had been made. Now a mediator is not for one party only; whereas God is only one*.
See also Acts 7:53 and Hebrews 2:2 for the “angels” deal.
Now, understanding from Scripture (I Timothy 2:5, Hebrews 8:6, 9:15, and 12:24) that a “Let Scripture Interpret Scripture” understanding of Christ being the Mediator would lead to at least understanding that He is the one that died as a ransom for “all”, and that since for a covenant to be in effect, there must be the death of the one who made it, Christ is the one who died in order for the New Covenant to be made effective. So, at least in that way, He is our mediator.
So, we come to the question of “who was the mediator of the Old Testament?” which is a question arising from Galatians 3:19.
Matthew Henry Commentary
Moses was only a mediator between God and the spiritual seed of Abraham; and therefore the law that was given by him could not affect the promise made to them, much less be subversive of it.
In the hand of a Mediator Hand usually signifies ministration; but as angels were ministers in giving the law, I consider “the hand of the Mediator” to denote the highest rank of service. The Mediator was at the head of the embassy, and angels were united with him as his companions. Some apply this expression to Moses, as marking a comparison between Moses and Christ; but I agree rather with the ancient expositors, who apply it to Christ himself.  This view, it will be found, agrees better with the context
But the footnote there, the , is by the editor I guess:
“Though some learned men have been of opinion that the mediator here mentioned is the Son of God, yet I think no reasonable doubt can be entertained as to its denoting Moses. Strictly speaking, Aaron, or rather the priesthood, was the mediator of the old covenant. It answers to the Great High-Priest, (ἀρχιερεύς,) Mediator, (μεσίτης,) and Surety, (ἔγγυος,) of the new covenant. But the reference seems here to the giving of the law: that was by Moses. ‘The law was given by Moses.’ (John 1:17.) God speaks to Moses, and Moses speaks to the people; and this arrangement was entered into by the express request of the people themselves. Moses himself says, ‘I stood between the Lord and you at that time. (Deuteronomy 5:5.) Philo calls Moses μεσίτης.” — Brown.
So, great Protestants aren’t in agreement on this. I don’t know myself. What do you think:
The mediator was Christ, or Moses, or who?