Galatians 3:19,20

Gal. 3:19, 20. "It was added because of transgressions, till the seed should come to whom the promise was made. And it was ordained by angels in the hand of a mediator. Now a mediator is not a mediator of one, but God is one." The apostle's design in mentioning the law's being ordained in the hand of a mediator, is to show the contrary of what the Jews and judaizing teachers supposed concerning that transaction of mount Sinai, between God and the people. When the law was ordained, they supposed it to be a merely legal transaction, that God acted therein merely as a sovereign righteous lawgiver in that affair, prescribing to the people legal terms of life and death; this is implied in their doctrine of justification by the works of the law. The apostle in what he here mentions of the transaction's being by a mediator, would show the contrary, viz. that it was not a mere legal transaction, but a transaction of grace; for a mere legal transaction of God with men does not admit of any mediator, but a transaction of grace does. Indeed, in a mere legal transaction, a middle person may be improved to act in the name of God, and appear for God to them, but such a middle person does not answer the notion of a mediator, as the apostle would signify. A mediator acts for both parties: he not only appears for God to man, and to act for God, but he also appears for man to God, and acts for man; for a mediator is not of one, he is not a middle person to act only for one of the parties. But God is one, i.e. God is but one of the parties transacting. If he acts as a middle person only on one side, he does not act as mediator; but a mediator appears for both parties, he acts for each to the other. A legal transaction would have admitted of a middle person to act for one side, viz. for God to man, but not for man to God, to intercede and plead for him. So was Moses. Moses was the mediator here spoken of, as is confirmed by Deuteronomy 5:5. God condescended, because the people could not bear the terrors of the law, to admit Moses as a mediator for them to stand before him, and hear and bear those terrors for them, as well as to act as his messenger to them. This shows plainly that it was a transaction of grace, wherein God was willing to admit a method to screen and save the poor fearful people, to screen them from the dreadful things apprehended, as well as from the terrible apprehension they had by hearing the dreadful voice, and seeing the raging fire. Therefore this is an evidence of what the apostle is arguing for, viz. that God in this transaction was not disannulling the transaction of grace, or that gracious covenant that had before been established with Abraham; he was now only building on that foundation that was then laid, and not setting it aside by this transaction that seemed to have an appearance of a legal transaction. This inference is made very much after the same manner with many others from transactions and passages of the Old Testament in the epistle to the Hebrews, and here and there in other epistles. And this reasoning is not so far fetched, and the arguments so much out of sight, as some may imagine. The words might be paraphrased thus: "In that transaction of mount Sinai, when the law was given, a mediator was made use of, and the notion of a mediator is, one that appears and pleads for both parties, one with the other. This mediator therefore that was admitted, did not only transact for God, who in the transaction was but one party, but also appeared and pleaded for the other party also with God, which shows that it was not a merely authoritative and legal, but a gracious, transaction." The 20th verse comes in as a kind of parenthesis, or a short exegetical digression, just to explain the meaning of the word mediator, which the apostle had used, because the argument he intended his readers should conceive from it, depended on their understanding what a mediator was; and therefore he was willing to let them know that, by a mediator, he did not only mean a middle person to act for God towards the people, but also one to act and plead for the people towards God. The apostle's words therefore may be otherwise paraphrased thus: "The law was ordained by angels in the hands of a mediator, i.e. in the hands of a middle person who appeared and pleaded for each party with the other, and not merely for God, who was but one party."

Gal. 4:21-23