Genesis 1:6-8
Genesis 1: 6 to 8
6 And God said, Let there be an expanse in the midst of the waters, and let it be a division between waters and waters.
7 And God made the expanse, and divided between the waters that are under the expanse and the waters that are above the expanse; and it was so.
8 And God called the expanse Heavens. And there was evening, and there was morning -- a second day.