Galatians 3:19 - Wesley's Explanatory Notes

It — The ceremonial law. Was added — To the promise. Because of transgressions — Probably, the yoke of the ceremonial law was inflicted as a punishment for the national sin of idolatry, Exodus 32:1, at least the more grievous parts of it; and the whole of it was a prophetic type of Christ. The moral law was added to the promise to discover and restrain transgressions, to convince men of their guilt, and need of the promise, and give some check to sin. And this law passeth not away; but the ceremonial law was only introduced till Christ, the seed to or through whom the promise was made, should come. And it was ordained by angels in the hand of a mediator — It was not given to Israel, like the promise to Abraham, immediately from God himself; but was conveyed by the ministry of angels to Moses, and delivered into his hand as a mediator between God and them, to remind them of the great Mediator.