The phrase "the four corners of the earth" occurs a few times in scripture but every time it's in the context of the millennial kingdom, it's never used in any other context.
The Four Corners of the Earth
Circle, sphere: ח֣וּג – chug
Circle, sphere: ח֣וּג - chug * to draw a circle, to circumscribe, Job 26:10. * masc. circle, sphere, * fem. compass, compasses, Is 44:13.
March 12th
If you want to believe that earth is flat no one's going to stop you. However nothing in the Bible, either in the meaning of words or in the context of passages, requires you to believe that earth is flat and has an edge.