1 God, then, was made man, and the Lord did Himself save us, giving us the token of the Virgin. But not as some allege, among those now presuming to expound the Scripture, [thus:] “Behold, a young woman shall conceive, and bring forth a son,” as Theodotion the Ephesian has interpreted, and Aquila of Pontus, both Jewish proselytes. The Ebionites, following these, assert that He was begotten by Joseph; thus destroying, as far as in them lies, such a marvellous dispensation of God, and setting aside the testimony of the prophets which proceeded from God.
For truly this prediction was uttered before the removal of the people to Babylon; that is, anterior to the supremacy acquired by the Medes and Persians. But it was interpreted into Greek by the Jews themselves, much before the period of our Lord's advent, that there might remain no suspicion that perchance the Jews, complying with our humour, did put this interpretation upon these words. They indeed, had they been cognizant of our future existence, and that we should use these proofs from the Scriptures, would themselves never have hesitated to burn their own Scriptures, which do declare that all other nations partake of [eternal] life, and show that they who boast themselves as being the house of Jacob and the people of Israel, are disinherited from the grace of God.
Source: Adversus haereses (New Advent)