Leolaia, I truly respect your opinions and your craftiness for supporting what you say with research. However (oh no!), the reason I mentioned how a circle would not be associated (within this discussion) with a flat surface is because of Finkelstein's reference regarding Daniel 4:10-11 (his post 1143), which prompted King Solomon to inform me that "And neither circles or spheres have corners (much less 4 corners)." You make a fine point by mentioning the "circle of the earth" as in Isaiah 40:22 to suggest a circular land mass on a flat surface. But Job 26:10 and Proverbs 8:27 refer to the circle over the "watery deep" or on the "surface of the waters". So, while that would agree with your presentation that a circular Earth was bounded by a circular ocean, it contradicts the references to corners of the earth (as many ancients believed, especially the Bible writers).
Yes, I see the point you are making, and it is reminiscent of what Ibn Ezra said about Isaiah 40:22 proving that the earth is not square in shape. I do not think however the phrase "four corners of the earth" necessarily invokes a distinctly "square-earth" cosmology. The reference is to the extremities on all four quadrants of the compass (north, east, west, south), or the four quarters of the earth, which need not require the earth to be shaped like a square.
The two Hebrew expressions have the sense of "outer limits" or "extremities". First, the phrase 'arba` kanpôt ha'arets (Isaiah 11:12, Ezekiel 7:2) is often translated in English "the four corners of the earth" (following the KJV) but the Hebrew kanap has more of the sense of "extremity" than "corner" per se; when it is applied to clothing it could refer to either corners or the loose end of the garment. When the expression occurs without the numeral (as in Job 37:3), English translations tend to translate it as "the ends of the earth". The actual word that specifically meant "corner" (i.e. an "angle" between two sides) was pinnah which usually referred to a corner of a building or structure (1 Kings 7:34, 2 Kings 14:13, 2 Chronicles 26:15, Nehemiah 3:31, Job 1:19, Proverbs 21:9, Ezekiel 43:20, 45:19, 3Q15 3:1, 5, 10, 11QTemple 30:5-8), which did not occur in reference to the earth. Kanpôt was rendered literally in the LXX and Theodotion (pterugas) and Symmachus rendered it with akra "extremities". Jeremiah 49:36 makes reference to the "four ends of the earth" and there the term is qetsôt, which the LXX renders as akra and Theodotion translates as teleutaia "endings". The same word (and its Aramaic cognate) occurs occasionally elsewhere to refer to the "ends of the earth" (Job 28:24, Isaiah 40:28, 41:5, 9, 4Q451 9:4, 11Q10 8:5).
It is in the Greek where there is an expression using the specific word for corner: gònia. The expression "the four corners of the earth" (tas tessaras gònias tès gès) in Revelation 7:1, 20:8 is what gave rise to the idiom in English. The use of gònias to refer to the extremities of the earth was not used in Greek outside of Jewish apocalyptic literature and later texts dependent on Revelation. The earliest possible example of this expression is in 1 Enoch 18:2: "I saw the foundation of the earth and the cornerstone of the earth (ton lithon tès gònias tès gès). I saw the four winds bearing the earth and the firmament of heaven". This translates the original Aramaic; the wording however is ambiguous and could be parsed incorrectly as "I saw the stone of the corners of the earth, I saw the four winds etc." This is very close to what is stated in Revelation 7:1: "After this I saw four angels standing at the four corners of the earth restraining the four winds of the earth". So what was originally a reference to the earth's cornerstone became a reference to the "corners of the earth". The reference to the four winds in 1 Enoch and Revelation was typical of the ANE re the different winds at the four cardinal points of the compass, cf. Pliny the Elder: "The ancients reckoned only four winds corresponding to the four parts of the world....There are two in each of four quarters of the heavens" (Historia Naturalis, 2.119). The cosmology in the Book of Watchers construes the winds as supporting not only the earth underneath but the heavens themselves: "I saw how the winds stretch out the height of heaven. They stand between earth and heaven; they are the pillars of heaven" (18:3). This explicates the cosmological statement in Job 26:7 regarding the north being stretched over the void and the earth upon nothing.
It should also be pointed out that the true extremities lay beyond the encircling ocean in much of the ANE tradition. The Babylonian map of the world depicts seven islands beyond the encircling ocean, including probably Dilmun, the paradise of the gods (where Utnapishtim lives in immortality). The typical Greek cosmography posited a world-encircling Okeanos and beyond it lay the Fortunate Islands and the Elysian Fields in the west (where the blessed live forever), the island of Alba in the east, and Hyperborea in the north where the Hyperborean winds originate from. Josephus similarly stated that the Essenes believed that the righteous dead reside in the Islands of the Blessed beyond the Okeanos, and clearly he has in mind the kind of cosmography that occurs in the Book of Parables. Enoch journeyed to the west to a river of fire and the fire of the west (which is responsible for the sunsets) and came to "the great sea of the west" (17:7) and beyond it lay mountains of jewels and "beyond these mountains is a place, the edge of the great earth, where the heavens come to an end, and I saw a great chasm among pillars of heavenly fire," and beyond the chasm was "a place that was neither firmament of heaven above, nor firmly founded earth beneath it" (18:12). This was the location of the prison of the fallen angels and rebellious stars. Meanwhile, towards the east at the extremities of the world lay the mountain of God and the tree of life (ch. 24); this is where Enoch later is placed where he lives eternally. Other Jewish sources refer to Paradise as at the eastern extremity of the world, at a place that is either already part of heaven or where the gates of heaven are located. So the extremities of the earth were not necessarily contained within the confines of the world ocean. There was a lot of ambiguity and speculation on what lay beyond the confines of the known world, a realm that was both (or neither) earth and heaven, where both heaven and the underworld were accessible. Partly this ambiguity was because earth was usually conceptually opposed to both heaven and the ocean; the realm of the ocean and what lay beyond the ocean was liminal between these two binary oppositions. It is not inconceivable that some could have thought of "corners" laying beyond the world ocean, just as the Babylonian Mappa Mundi depicts triangular islands at the extremities.
At some point, we would have to assume that they believed the ocean surrounding the circle-Earth was square and not a circle in order to support the "corners" theory (if they believed that the term came from a square flat earth).
Yeah I don't think that's necessarily the case. And "corner" does not necessarily imply "square" either. BTW there is an interesting parallel to the biblical "inscribing a circle on the deep" in Herodotus who described the maps made by ancient cartographers (such as Hecataeus of Miletus, reminiscent somewhat to the Babylonian Mappa Mundi), "who draw Okeanos flowing around the earth, which is made wheel-shaped as if by compasses (eousan kukloterea hòs apo tornou)" (Historiae, 4.36).
I think that a lot of that is subject to speculation and is all inconclusive.
I agree with you there.