From Augustine, ‘De genesi ad litteram’ (The literal meaning of Genesis), book 2, chapter 9 (tr. J.H.Taylor, 1982):
“It is frequently asked what our belief must be about the form and shape of heaven according to Sacred Scripture. Many scholars engaged in lengthy discussions on these matter, but the sacred writers with their deeper wisdom have omitted them. Such subjects are of no profit for those who seek beatitude, and, what is worse, they take up precious time that ought to be given to what is spiritually beneficial. What concern is it of mine whether heaven is a sphere and the earth is enclosed by it and suspended in the middle of the universe, or whether heaven like a disk above the earth covers it on one side?
“But the credibility of Scripture is at stake, and as I have indicated more than once, there is danger that a man uninstructed in divine revelation, discovering something in Scripture or hearing from it something that seems to be at variance with the knowledge that he has acquired, may resolutely withhold his assent in other matters where Scripture presents useful admonitions, narratives, or declarations. Hence, I must say briefly that in the matter of the shape of heaven the sacred writers knew the truth, but that the Spirit of God, who spoke through them, did not wish to teach men these facts that would be of no avail to their salvation.”