ὃς ἀποδώσει ἑκάστῳ κατὰ τὰ ἔργα αὐτοῦ

Says The relative ὃς, whose antecedent is τοῦ θεοῦ (2:5), introduces a future: ἀποδώσει ἑκάστῳ κατὰ τὰ ἔργα αὐτοῦ, "will repay each one according to his deeds" (BSB).

Says Swete's LXX (checked on the scans) has ὅτι σὺ ἀποδώσεις ἑκάστῳ κατὰ τὰ ἔργα αὐτοῦ at Ps 62:12 (MT 62:13; LXX 61:13), and ὃς ἀποδίδωσιν ἑκάστῳ κατὰ τὰ ἔργα αὐτοῦ at Prov 24:12. Paul has the psalm's future in the third person, with the relative ὅς of Proverbs. The Hebrew is treated in note.language.Rom.2.6.ps-62-12-prov-24-12.

Says κατά with the accusative states the norm: the verdict will correspond to the deeds. Paul uses different prepositions for justification: ἐξ ἔργων νόμου οὐ δικαιωθήσεται (3:20), χωρὶς ἔργων νόμου (3:28), and εἰ … ἐξ ἔργων ἐδικαιώθη (4:2).

Implies Judgment according to deeds is real and impartial, and it is not a second way of salvation alongside faith (2:6, 16; 3:9, 20, 23, 28).

Uncertain Which conservative reading explains those who "by perseverance in doing good seek glory, honor, and immortality" (2:7). Conservative evangelicals hold both; neither is preferred here. - (a) Law standard. 2:7 states what the law requires, which no one meets apart from Christ. Grounds: 2:12–13 makes the law the measure of the judgment, and 3:9–20 concludes that no one is righteous. - (b) Fruit of faith. 2:7 describes believers, whose perseverance is the fruit of saving faith and grace. Grounds: the positive language of 2:7, 10, the Spirit-wrought obedience of 2:26–29, and 8:4.