Ezekiel 1:27
25 Then there was a voice from above the platform over their heads when they stood still. 26 Above the platform over their heads was something like a sapphire shaped like a throne. High above on the throne was a form that appeared to be a man. 27 I saw an amber glow like a fire enclosed all around from his waist up. From his waist down I saw something that looked like fire. There was a brilliant light around it, 28 like the appearance of a rainbow in the clouds after the rain. This was the appearance of the surrounding brilliant light; it looked like the glory of the Lord. When I saw it, I threw myself face down, and I heard a voice speaking.
Revelation 10:1
1 Then I saw another powerful angel descending from heaven, wrapped in a cloud, with a rainbow above his head; his face was like the sun, and his legs were like pillars of fire. 2 He held in his hand a little scroll that was open, and he put his right foot on the sea and his left on the land. 3 Then he shouted in a loud voice like a lion roaring, and when he shouted, the seven thunders sounded their voices. 4 When the seven thunders spoke, I was preparing to write, but just then I heard a voice from heaven say, “Seal up what the seven thunders spoke and do not write it down.” 5 Then the angel I saw standing on the sea and on the land raised his right hand to heaven
Notes and References
"... The ”rainbow” also has Old Testament precedent: “The rainbow is based on an allusion to the throne vision in Ezekiel 1:27–28.” In light of the gemstone vocabulary, it is certain that John has the enthroned divine man vision of Ezekiel 1 in view here. It is true that, in LXX Ezekiel 1:28, the “brightness . . . like the appearance of a bow” around the throne of God and its occupant, utilizes the word tokson, which is not the vocabulary of Revelation 4:3. The latter term is found in the same vision, though, in Ezekiel 10:1, securing the identification of John’s point of reference ..."
Heiser, Michael S. The Old Testament in Revelation: Notes from the Naked Bible Podcast (p. 89) Naked Bible Press, 2021