Wherefore then serveth the law? — Literally, What then is the Law? What is its object or function? If it did not affect the promise, what did it do? The Apostle proceeds to answer this question.
It was added. — It was not a part of the original scheme, but came in as a sort of marginal addition. It was, as it were, a parenthesis in the design of Providence. The direct line of God’s dealings with man ran through the promise and its fulfilment. The Law came in by the way.
Because of transgressions. — It has been usual to give to this one of two opposite interpretations, to make it mean (1) to check or put down transgressions; (2) to multiply and increase transgressions, as in Romans 5:20. The expression seems wide enough to cover both ideas. The Law was given “because of transgressions:” i.e., it had its object in transgressions. Its original purpose was to make them known, and by imposing a penalty to check them; its real effect was to provoke and enhance them. The expression “because of transgressions” leaves it ambiguous which of these points is meant, or rather, it includes them all.
Till the seed should come to whom the promise was made. — By “the seed” is meant, as above, in Galatians 3:16, Christ, the Messiah. The promise is said to have been made to Him in whom it is fulfilled, just as, in Galatians 3:14, Christians are said to “receive the promise” — i.e., the fulfilment of the promise “of the Spirit.”
Ordained by angels. — The idea of angels having had a share in the giving of the Law appears in Deuteronomy 33:2 : “The Lord came from Sinai... He shined forth from mount Paran, and He came with ten thousands of saints.” For “saints” the LXX. substitutes, in the next verse, “angels.” Similar allusions are found at the end of St. Stephen’s speech (Acts 7:53): “Who have received the law by the disposition (as ordinances) of angels, and have not kept it;” and in Hebrews 2:2 : “If the word spoken by (through) angels was stedfast.” In this last instance, as in the present passage, the ministration of angels employed in it is quoted as showing the inferiority of the Law to the Gospel. In St. Stephen’s speech and in Josephus (Ant. xv. 5, 3) the same ministration is appealed to as enhancing the dignity of the Law. The different point of view is natural enough, according as the subject is regarded from the side of man or from the side of God.
In the hand of a mediator. — Through the instrumentality of a third person, distinct from the contracting parties — i.e., in this case, Moses. The term “mediator” was commonly applied to Moses in the Rabbinical writings, and appears to be hinted at in Hebrews 8:6, where our Lord is spoken of as “a mediator of a better covenant.” Many of the fathers, following Origen, took the mediator here to be Christ, and were thus thrown out in their interpretation of the whole passage.