Romans 9:20

Nay but. The Greek word order and literal meaning of the clause is, “O man, but indeed you, who are you?” An emphatic contrast is suggested between mere man and God. Paul reminds man that his real relation to God is that of a creature to his Creator. Therefore, what man has any right to complain or to question God’s dealings? Instead of answering the questions raised in the previous verse, Paul addresses himself to the spirit that prompted them.

Repliest. Greek antapokrinomai, literally, “to answer by contradicting.” The only other NT occurrence of this verb is in Luke 14:6, where it is used to describe the inability of the Pharisees to “answer” Jesus. Likewise, in this verse the word may suggest contradiction to an answer that God has already given.

Thing formed. Greek plasma. The related verb, plasso, means “to mold,” or “to shape,” as with clay or wax. Comparing God’s power to the control of a potter over his clay was a familiar OT idea. Paul here cites from Isa. 29:16; 45:9 (cf. Isa. 64:8; Jer. 18:6). It is particularly appropriate for Paul to make use of these words of Isaiah, since both writers are considering the same subject — God’s formation of Israel as a nation and His consequent unquestionable right to deal with the nation as He deems best.

Why hast thou? The presumptuousness of lodging a complaint against God is forcefully illustrated. As Creator, God has the right to distribute gifts according to His will (see on verse 11).