To Florus 1.138
These arguments concern the apostle's testimony. In Isaiah, however, from whom Paul took the statement itself, God is so far from deterring rational creatures from examining his judgment that he deigns to explain the reasoning of his dealings, lest he seem to have acted by power alone rather than justice. Through the same prophet he had said: “Cease acting perversely, learn to do good, help the oppressed; and come, argue with me, says the Lord” (Isaiah 1:16–18). Here likewise he announces to the Jewish people suffering in captivity that the time of redemption is approaching, when they will return to their own land. He discloses the reason both for their preceding distress and for their coming joy.
He says: “Let heaven above feast, and let the clouds scatter righteousness; let mercy arise from the earth, and let righteousness arise together with it. I am the Lord God who created you; making you better, I prepared you like a potter's clay. Will the plowman plow the earth all day? (Isaiah 28:24) Does the clay say to the potter, ‘What are you doing? You are not working; you have no hands’? Does what is molded say to the one who molded it, ‘Did you mold me wisely?’ (compare Isaiah 29:16) Or does someone say to a father, ‘What will you beget?’ and to a mother, ‘What will you give birth to?’ For thus says the Lord God, the Holy One of Israel, who made the things to come: ‘Question me about my sons and daughters, and give me instructions about the works of my hands. I made the earth and the human being upon it; with my own hand I established heaven; I commanded all the stars. I have raised up a king with righteousness, and all his ways are straight. He will build my city and bring back my people's captivity, not for a reward or for gifts,’ says the Lord of Hosts” (Isaiah 45:8–13, LXX-based wording).