Romans. Craig S. Keener

But he identifies God’s covenant faithfulness with his righteousness (see comment on 1:17), and insists that it is God as Israel’s judge, rather than disobedient Israel, who will be shown righteous.5 (That his righteousness and faithfulness also include a continuing plan for Israel will be clarified later in 11:1–32, esp. 11:25–32.)

      “Everyone is a liar” (3:4) comes from Ps 116:11 (115:2 lxx), anticipating Paul’s texts for human sinfulness in 3:10–18 (esp. 3:13). Because it comes from the “Hallel” psalms used in festivals (at least in Jerusalem), its wording may have been familiar. But Paul more explicitly cites Ps 51:4, where the psalmist admits his guilt and God’s righteousness. Because the current version of the psalm already identified it with David’s repentance, Paul probably anticipates here God’s forgiveness of David without works in Rom 4:6–8.