Since the words "son" and "children" do not signify only the immediate sons or children of a given person or generation, but, in Hebrew usage, descendants in general, however far they continue, the promise applies here to the whole future posterity of the Jews.
It applies without limitation of time to those descendants who will turn to Christianity; cf. the note on Mt 1:1.
"And to all who are afar off." By those afar off are meant here not the distant descendants of the Jews, for that is included in "your children."
Nor are the Jews scattered in distant lands among the Gentiles and their descendants meant.
For the words "to you and to your children" already contain the idea of all Jews, wherever they may live, since this promise was given to all Jews as the people of the covenant.
Rather, the Gentiles are meant here; cf. Theophylact. They are to be called into the kingdom of Christ, all nations throughout all future time.
The very course of the Apostle's speech requires this meaning of the words "afar off." In it the circle of those who share in the promise gradually widens.
First come the Jews, then their descendants wherever and whenever they may live, and finally the Gentiles.
Christ Himself spoke repeatedly of the calling of the Gentiles, and He commanded the Apostles to preach the Gospel to all nations and to baptize them; Mt 28:19; Acts 1:8 and others.
The Apostle Peter speaks of this here, but not openly. He speaks in a veiled way, perhaps because the idea of a universal Messiah, a Messiah also of the Gentiles, did not yet fit into the minds of the Jews.
It seemed scandalous to them; cf. Jn 7:35-36 and note. The Apostle spared their weakness, especially since there was now no special need to unfold the calling of the Gentiles into the Messiah's kingdom.
Later the Apostle explained it more fully; see chapters 10 and 11.
"As many as the Lord shall call." These words contain a limitation of the preceding words.
The promise of the outpouring of the gifts of the Holy Spirit is given to all, but it will be fulfilled only upon those whom the Lord calls into His kingdom.
That is, it will be fulfilled upon those who turn to faith in Christ, who repent and are baptized in the name of Jesus Christ.
This depends upon God's calling and upon man's free will; cf. Jn 6:44 and note.