Differences in justification method in Romans 3:30

Question

Romans 3:30

εἴπερ εἷς ὁ θεὸς ὃς δικαιώσει περιτομὴν ἐκ πίστεως καὶ ἀκροβυστίαν διὰ τῆς πίστεως._(NA28)

since God is one—who will justify the circumcised by faith and the uncircumcised through [∅] faith. _(ESV)

There are two differences I see between the first and second statements about justification:

1. The preposition is different.
2. The second statement adds the article to the abstract noun.*

I think the article is probably anaphoric, referring back to the first πίστεως (i.e. «through that same faith» or some such). Some translations indicate that. I’m at a loss about the meaning of the shift in prepositions. The ESV has reflected the shift by using two different English prepositions, but the difference isn’t obvious to me in English either.

What is the reason for these differences?

---

_{*Notably, the object of a preposition. I think most people would agree that it isn’t necessary for definiteness there, so its presence probably indicates something else.}

Answer 1

Some think Paul uses these different modes of expression randomly without any purpose.

"There is no distinction as to the meaning to be sought between ἐκ πίστεως (by faith) and διὰ πίστεως (through faith,) as Paul uses both forms indiscriminately; ἐκ, for example, in 1:17, 3:20, 4:16, &c., and διά in 3:22, 25, Gal. 2:16, and sometimes first the one, and then the other, in the same connection." (Hodge Commentary on Romans, P157)

Others do see a possible reason. I think the idea under that view is that for the Jew the basis of the faith is assumed and settled (indicated by using 'by') but for the gentile they are entering 'through' (from one place to another not best indicated by 'by' but implied by 'through'.

For example:

"To the genuine Jew, saving faith, as to its germ, is something already at hand, and justification arises from the completion of the same, just as the fruit from the tree. But to the Gentile, faith is offered as a foreign means of salvation." (Lange, Commentary on Romans, p137)