Clement of Alexandria, on Rom 1:17

And if to Abraham on his believing it was counted for righteousness; and if we are the seed of Abraham, then we must also believe through hearing. For we are Israelites, who are convinced not by signs, but by hearing. Wherefore it is said, "Rejoice, O barren, that barest not; break forth and cry, thou that didst not travail with child: for more are the children of the desolate than of her who hath an husband." ...And if the same mansions are promised by prophecy to us and to the patriarchs, the God of both the covenants is shown to be one. Accordingly it is added more clearly, "Thou hast inherited the covenant of Israel," speaking to those called from among the nations that were once barren, being formerly destitute of this husband, who is the Word,-desolate formerly,-of the bridegroom. "Now the just shall live by faith," which is according to the covenant and the commandments; since these, which are two in name and time, given in accordance with the [divine] economy-being in power one-the old and the new, are dispensed through the Son by one God. As the apostle also says in the Epistle to the Romans, "For therein is the righteousness of God revealed from faith to faith," teaching the one salvation which from prophecy to the Gospel is perfected by one and the same Lord.