Augustine of Hippo

One who diligently considers what darkness is really finds only the absence of light. Thus it said, "darkness was over the abyss," as if to say, "There was no light over the abyss." Hence, this matter that is ordered and distinguished by the next work of God is called the invisible and unformed earth and the deep that is lacking light. This is what was above called heaven and earth, like the seed of heaven and earth.