The Barddas of Iolo Morganwg, Vol. I., ed. by J. Williams Ab Ithel, , at sacred-texts.com
Question. Why do we say, heaven above, and hell beneath, where there can be no highest in respect of any being, or lowest in respect of any existence? And why God in the highest, and Cythraul in the lowest?
Answer. Because the light is always highest, and above our heads, and it is in the light that God is found, and there can be no heaven, except in the light; and God and heaven always go together with light. And the darkness is always the lowest, and Cythraul and hell go together with it.