Ezekiel 10:1-2

Then I looked, and behold, in the expanse (firmament) that was over the heads of the cherubim there appeared something [glorious and brilliant] above them looking like a [huge] sapphire stone, formed to resemble a throne. And the LORD spoke to the man (seventh angel) clothed in linen and said, “Go between the whirling wheels under the cherubim; fill your hands with coals of fire from between the cherubim and scatter them over the city.” And he entered as I watched. [Rev 8:5]