Ezekiel 1:9

Two of the wings were in the act of flying, so stretched out that the extremity of each touched a wing of a neighboring living creature, similarly stretched out. This was only when they were in motion. See Ezekiel 1:24.

They went every one straight forward - The four together formed a square, and never altered their relative position. From each side two faces looked straight out, one at each corner - and so all moved together toward any of the four quarters, toward which each one had one of its four faces directed; in whatsoever direction the whole moved the four might be said all to go “straight forward.”