Ezekiel 1:22-25

The likeness of the firmament above the heads of the living creatures was like the color of an awesome crystal, stretched out over their heads. And under the firmament their wings spread out straight, one toward another. Each one had two which covered one side, and each one had two which covered the other side of the body. When they went, I heard the noise of their wings, like the noise of many waters, like the voice of the Almighty, a tumult like the noise of an army; and when they stood still, they let down their wings. A voice came from above the firmament that was over their heads; whenever they stood, they let down their wings.