Precatus est Moyses in conspectu Domini, Dei sui, et dixit: Quare, Domine, irasceris in populo tuo? Parce iræ animæ tuæ: memento Abraham, Isaac et Iacob, quibus iurasti dare terram fluentem lac et mel. (Offertory for the Twelfth Sunday after Pentecost - cf. Exodus xxxii: "Moses prayed in the sight of the Lord his God, and said: 'Why, O Lord, is thine indignation enkindled against thy people? Let the anger of thy mind cease; remember Abraham, Isaac, and Jacob, to whom thou didst swear to give a land flowing with milk and honey'.")
It might be assigned as a reason for the Law being given to the Jews rather than to other peoples, that the Jewish people alone remained faithful to the worship of one God, while the others turned away to idolatry; wherefore the latter were unworthy to receive the Law, lest a holy thing should be given to dogs.
But this reason does not seem fitting: because that people turned to idolatry, even after the Law had been made, which was more grievous, as is clear from Exodus xxxii and from Amos v, 25-26: "Did you offer victims and sacrifices to Me in the desert for forty years, O house of Israel? But you carried a tabernacle for your Moloch, and the image of your idols, the star of your god, which you made to yourselves." Moreover it is stated expressly: "Know therefore that the Lord thy God giveth thee not this excellent land in possession for thy justices, for thou art a very stiff-necked people": but the real reason is given in the preceding verse: "That the Lord might accomplish His word, which He promised by oath to thy fathers Abraham, Isaac, and Jacob."
What this promise was is shown by the Apostle, who says that "to Abraham were the promises made and to his seed. He saith not, 'And to his seeds,' as of many: but as of one, 'And to thy seed,' which is Christ." And so God vouchsafed both the Law and other special honors to that people, on account of the promises made to their Fathers that Christ should be born of them. For it was fitting that the people, of whom Christ was to be born, should be marked by a special sanctification, according to the words of Leviticus xix, 2: "Be ye holy, because I . . . am holy." Nor again was it on account of the merit of Abraham himself that this promise was made to him, that is, that Christ should be born of his seed: but of gratuitous election and vocation. Hence it is written: "Who hath raised up the just one form the east, hath called him to follow him?"
It is therefore evident that it was merely from gratuitous election that the patriarchs received the promise, and that the people sprung from them received the law; according to Deuteronomy iv, 36-37: "Thou didst hear His words out of the midst of the fire, because He loved thy fathers, and chose their seed after them."
Saint Thomas Aquinas
S.Theol. I-II, 98, iv
S.Theol. I-II, 98, iv