In Augustine's Confessions, book XII, chapters xvi–xvii (23–24), he writes about his disagreements with others over the proper interpretation of the Creation account in Genesis 1. Augustine holds that Genesis 1:1 refers to the out-of-time creation of the spiritual realms and a formless "earth," while his opponents argue that "heaven and earth" refer only to the visible creation.
He quotes their views as follows:
They say: 'Although this may be true, yet Moses did not have these two things in mind when by the revelation of the Spirit he said: "In the beginning God made heaven and earth" (Gen. 1:1). By the word "heaven" he did not mean the spiritual or intellectual creation which continually looks on God's face, nor by the word "earth" did he intend formless matter.' What then? They say: 'What that man had in mind was what we say he meant, and this is what he expressed in those words.' [...]
'By the phrase "heaven and earth"', they say, 'Moses meant to signify in general and concise terms the entire visible world, so that thereafter under the successive days he could arrange one by one each category which it pleased the Holy Spirit to list in this way. The character of the people addressed was rough and carnal, and so he decided to present to them only the visible works of God.' (XII.xvii)
In the Confessions Augustine often argues against the Manicheans, but that's apparently not the case in this section. The people in view here "honour your holy scripture written by that holy man Moses and agree with us that we should follow its supreme authority" (XII.xvi), and the Manicheans certainly didn't do that.
Do scholars have any idea who these opponents were? Do their writings survive?