Operation fishbowl? the firmament: what it is, how it functions, what it's made of, and where it appears in scripture. this is divine engineering. What Is the Firmament? The firmament (Hebrew: raqia) is described as a vast solid structure — a dome, vault, or expanse — that divides the waters above from the waters below. It is not poetic metaphor. It is architectural. Structural. It was created on Day 2, before the sun, moon, or stars. Scriptural Foundation Let’s start with the blueprint: Genesis