“Four corners of the earth” is taken as a piece of ancient cosmology, embedded in the Bible. But the Bible historicizes this cartography as it historicizes much else.
The phrase “four corners” isn’t applied to land until Isaiah 11:12, which speaks of the Lord calling together His dispersed people from the “four corners of the earth.” Ezekiel uses the same phrase, but translators rightly translate it as “four corners of the land” (Ezekiel 7:2) because the focus is on Israel.
Prior to Isaiah, there are four corners to altars (Exodus 27:2, 4) and the ark (Exodus 25:26). Israelites wear four-cornered garments (Deuteronomy 22:12) because they are living altars. The land of Israel is, implicitly, four-cornered, since it is an altar-land. As the holy land, it’s appropriate that Israel be squared. This is why Yahweh shows Abraham a land to north, south, east, and west (Genesis 13:14. Yahweh assures Jacob that his seed will spread out to the four directions as well (28:14).Taking a cue from Isaiah 11, we might say that the earth becomes four cornered when Israel is scattered. The presence of the holy people among the Gentile world stretched the boundaries of “holy space,” so that the earth – or at least the Mediterranean world with which the Bible is concerned – was squared off. From the time of the exile, “four” becomes a common number for the Gentile world: there are four empires and four kings and four beasts and four metals in the statue of Nebuchadnezzar’s vision. But the Gentile world becomes fourfold only when the Jews inhabit it.