What do the spheres of the earth mean?

Did you mean to say when speaking of the spheres that they are all equally distant as regards space from us?

No—the lower spheres are nigh to your earth—the highest is far beyond the sun. The sixth sphere is if measured by distance nearer to the sun than it is to the earth.

I heard a discussion the other night about the sun, as a source of light and heat—will you favour me with something on that point?

There is no more heat proceeding from the sun than there is from the earth. The heat is bottled up in the sun in the same way as it is in the earth, and the sun is merely a reflector of the light that it gets and which all the worlds in space get from the great and eternal Source of Light.

—Hafed, Prince of Persia