'Expanse' in the Bible

And there was the likeness of an expanse over the heads of the living creature, as the look of the terrible crystal, stretched forth over their heads above.

And under the expanse were their wings straight, the one toward the other: every one had two which covered on this side, and every one had two which covered on that side their bodies.

and there was a voice from above the expanse that was over their heads. When they stood, they let down their wings.

And above the expanse that was over their heads was the likeness of a throne, as the appearance of a sapphire stone; and upon the likeness of the throne was a likeness as the appearance of a man above upon it.

And I looked, and behold, in the expanse that was over the head of the cherubim there appeared above them as it were a sapphire stone, as the appearance of the likeness of a throne.