[OT] Firmament

Firmament (Gen 1:6) (jumping ahead to the concept of firmament to provide context for v.2)

6 ¶ And God said, Let there be a firmament in the midst of the waters, and let it divide the waters from the waters.  

• The Hebrews conceived the universe as water, with a bowl shaped "firmament" over the flat earth holding back the waters.  the Stars, sun and moon were placed in the firmament.  Rain came through the "windows of heaven," and the fountains of the deep"  came from the universal waters below the earth.
  

•  Hebrew Cosmology diagram.  See also here or here.
  

• The root of "firmament" means "hammer out", implies a horizontal area [UC 31]

• Mesopotamian mythology shows after Marduk (or other various deities from other times/places) vanquished Tiamat, goddess of the world-ocean, depicted as a great sea-monster and other monster-like creations she made to help her in her combat. After he had slain his chief enemy, he cut her carcass horizontally, dividing it into two halves, one on top of the other, and out of the upper half, he formed the heavens, and out of the lower half, the earth, including the sea/"deep."  [UC 32-33, 49-50]
  

• From the Babylonian account of creation (Tablet IV, 137-140):

He split her like a fish into two parts;
The one half of her he set up and laid therewith the beams of the heavens*
He pulled down a bar and stationed a watch,
He enjoined them not to let her waters go forth

*(cf. Psalms 104:3 "Who hast laid the beams of thy chambers on the waters."  Note the  psalm is about the creation).

• Genesis recognizes the Canaanite myth, but refutes it.  No weapons, no carved body or segments, just physical unfolding taking the place of the mythical train of events