Four living creatures carried a firmament or some kind of expanse above them, and Ezekiel saw something above the firmament,

“And above the firmament over their heads was the likeness of a throne, in appearance like a sapphire stone; on the likeness of the throne was a likeness with the appearance of a man high above it” (Ezekiel 1:26).

The prophet saw the Lord reigning as King, but the Lord also had the appearance of a man, because Ezekiel saw the one who would come down to Earth and live as a man, although the prophet had begun his writing by saying that he saw visions of God (Ezekiel 1:1), which means that the Lord who became a man, was also God.