Charles Hodge on Ephesians 3:5

V. 5. God by revelation had made known to Paul a mystery, or purpose, which was not revealed as it now was to the apostles. That the Gentiles were to partake of the blessings of the Messiah’s reign, and to be united as one body with the Jews in his kingdom, is not only frequently predicted by the ancient prophets, but Paul himself repeatedly and at length quotes their declarations on this point to prove that what he taught was in accordance with the Old Testament; see Rom. 9, 25-33. The emphasis must, therefore, be laid on the word as. This doctrine was not formerly revealed as, i. e. not so fully or so clearly as under the Gospel.

The common text reads ἐν ἑτέραις γενεαῖς, in other generations. But most editors, on the authority of the older MSS., omit the preposition. Still the great majority of commentators interpret the above phrase as determining the time, and render it, during other ages. To this, however, it is objected that γενεά never means, an age in the sense of period of time, but always a generation, the men of any age, those living in any one period. If this objection is valid γενεαῖς must be taken as the simple dative, and υἱοῖς τῶν ἀνθρώπων be regarded as explanatory. The passage would then read, "Which was not made known to other generations, i. e. to the sons of men," &c. But in Acts 14, 16. 15, 21, and especially in Col. 1, 26 (ἀπὸ τῶν αἰώνων καὶ ἀπὸ τῶν γενεῶν), γενεά is most naturally taken in the sense of age, or period of duration. In the same sense it is used in the Septuagint, Ps. 72, 5. 102, 25. Is. 51, 8.

As it is now revealed to his holy apostles and to the prophets by the Spirit, ὡς νῦν ἀποκαλύφθη . . . . ἐν πνεύματι. The apostles and prophets of the new dispensation were the only classes of inspired men; the former being the permanent, the latter the occasional organs of the Spirit. They therefore were the only recipients of direct revelations. They are here called holy in the sense of sacred, consecrated. They were men set apart for the peculiar service of God. In the same sense the prophets of the old economy are called holy. Luke 1, 70. 2 Peter 1, 21. The pronoun his in connection with apostles may refer to God as the author of the revelation spoken of, or to Christ whose messengers the apostles were. ‘My knowledge of the mystery of Christ, which, in former ages, was not made known, as it is now revealed to his apostles,’ &c. By the Spirit, i. e. revealed by the Spirit. Πνεύματι, though without the article, refers to the Holy Spirit, the immediate author of these divine communications. It follows from the scriptural doctrine of the Trinity, which teaches the identity as to substance of the Father, Son, and Spirit, that the act of the one is the act of the others. Paul, therefore, refers the revelations which he received sometimes to God, as in verse 3; sometimes to Christ as in Gal. 1, 12; sometimes to the Spirit.