Ezekiel 10:9-11

9And I looked, and behold, four wheels beside the cherubim, one wheel beside one cherub, and another wheel beside another cherub; and the appearance of the wheels was as the look of a chrysolite stone.

10And as for their appearance, they four had one likeness, as if a wheel were in the midst of a wheel.

11When they went, they went upon their four sides; they turned not as they went, but to the place whither the head looked they followed it: they turned not as they went.