When you're stranding on the Earth it visually looks like the Sun is moving. They must have known it isn't the Sun that is actually moving across the sky, because they also knew the Earth is hung on nothing.
Job 26:7
7He stretcheth out the north over the empty place,
and hangeth the earth upon nothing.
We know today the earth is not moving. We know the sun moves on it's circuit through the sky. Our mind has been conditioned to view it the other way.
There is nothing else but the earth. This verse claims we are not part of a universe, because the universe is something. The alledged space between the earth and the moon is still something. It is made up of the same particles as the rest of creation. The alledged space above us in the firmament is still something, and literally the firmament above is all there is. The same area in size as the earth below.
Even this symbolic point in the verse declares the north as the "center" from which an imaginary line is being hung from. The north is being stretched out, so is the starting point outwards to the ends of the earth. The earth is not suspended in space in a vast universe. There is literally nothing else. What is seen in the firmament directly above earth is all there is. One single square creation. The length, the depth, the height, and the breadth (time) is what makes up creation. So the 8,000 years of existence is directly related to the 3 size dimensions of earth. Just a different use of math than the use modern science has given to describe a 14 billion year old universe. Which, this alledged universe is still hung on nothing. That universe is still up, down, out, and across. And allegedly flat as well, but even that has not been settled. It is just a larger square, because obviously the math with 14 billion years, is larger than 8,000 finite years.