Expositor's Bible Commentary Commentary Galatians 3:19

"What then is the law? It was added because of transgressions, till the seed should come to whom the promise hath been made; [and it was] ordained through angels by the hand of a mediator." — Galatians 3:19 (ASV)

To the question “What, then, was the purpose of the law?” Paul provides as his first answer that the law was added “because of transgressions” (GK 4126). That is, the law was given to make the transgressions known, perhaps even to encourage them or to provoke them to a new intensity (4:15). Though sin was in the world before God gave the law, sin was not always known as such; it was the law that revealed sin as sin. Hence, it may be said that it is the law that turns sin into transgression—transgression of law—and even accentuates it (Romans 5:20). In this act, law performs the function of showing one’s need of a Savior.

The second half of this verse carries the thought further by showing that the giving of the law was temporary (“until the Seed to whom the promise referred had come”) and inferior (because it was “put into effect through angels by a mediator”). Here the mediator is doubtless Moses who, as an agent of a mediated revelation, is brought forward in contrast to Abraham, to whom God made promises directly. The role of angels in the giving of the law is suggested in Dt 33:2 and Ps 68:17 and is referred to explicitly in Ac 7:53 and Heb 2:2.