A.T. Robertson Commentary Romans 3:5

"But if our righteousness commendeth the righteousness of God, what shall we say? Is God unrighteous who visiteth with wrath? (I speak after the manner of men.)" — Romans 3:5 (ASV)

What shall we say? (τ ερουμεν?). Rhetorical question, common with Paul as he surveys the argument.

Commendeth (συνιστησιν). This common verb συνιστημ, to send together, occurs in the N.T. in two senses, either to introduce, to commend (2 Corinthians 3:1; 2 Corinthians 4:2) or to prove, to establish (2 Corinthians 7:11; Galatians 2:18; Romans 5:8). Either makes good sense here.

Who visiteth the wrath (ο επιφερων την οργην). "Who brings on the wrath," "the inflicter of the anger" (Vaughan).

I speak as a man (κατα ανθρωπον). See Ga 3:15 for same phrase. As if to say, "pardon me for this line of argument." Tholuck says that the rabbis often used κατα ανθρωπον and τ ερουμεν. Paul had not forgotten his rabbinical training.