Jerome : Whenever our Lord Jesus Christ is called Abraham's offspring, this must be understood in the bodily sense of his generation from the stock of Abraham. But when it is applied to us who, receiving the Savior's word, believe in him and assume the dignity of Abraham's race, to whom the promise was made, then we should understand the offspring spiritually, as that of faith and preaching.… We must also note that, when the Lord is spoken of, Paul mentions promises in the plural—the promises are made to Abraham and his offspring—but when he speaks of those who through Jesus Christ are the offspring of Abraham, the promise is referred to in the singular, as in the present passage. — EPISTLE TO THE Galatians 2.3.29 Jerome : (Verse 29.) But if you are Christ's, then you are Abraham's offspring, heirs according to the promise. For the promises were made to Abraham and to his offspring. It does not say, "And to offsprings," referring to many, but referring to one, "And to your offspring," who is Christ. This is what I mean: the law, which came 430 years afterward, does not annul a covenant previously ratified by God, so as to make the promise void. For if the inheritance comes by the law, it no longer comes by promise; but God gave it to Abraham by a promise. However, as often as we, who have believed in him after receiving the message of the Savior, receive the nobility of the lineage of Abraham, to whom the promise was made, then we must spiritually receive the seed of faith and preaching. Furthermore, it should also be considered that when it speaks of the Lord, it pluralizes the promises made to Abraham and his offspring, that is, Christ Jesus. But when it speaks of those who are the offspring of Abraham through Christ, it designates the promise in the singular, as in the present passage: Therefore, you are the offspring of Abraham, heirs according to the promise. For it was fitting that what was said in the plural in Christ should be attributed to many individuals in the singular. It follows: — Commentary on Galatians John Chrysostom : Here, you observe, he proves what he had before stated concerning the seed of Abraham,-that to him and to his seed the promises were given. — Homily on Galatians 3 Oecumenius : "if you belong to Christ, then." If then you are the form and body of Christ, he says, it is fittingly that you are the seed of Abraham. For since previously he said that Christ is the seed of Abraham according to the flesh (and to that seed of Abraham the promises were given, that is, to Christ), now the same thing is summed up. If you are, he says, the body of Christ, you are also the seed of Abraham and heirs of the promise given to his seed; Christ is, he says, the author of these things for us, having made us his body, and therefore also introducing us into the seed of Abraham, not, however, the law. — Commentary on Galatians