Ezekiel 10:1

1. “Behold… as it were a sapphire stone, with the appearance of the likeness of a throne upon it” (LXX.). The glory of the Lord has returned from the threshold of the house (Ezekiel 9:3) and the prophet now sees it above the cherubim. If we follow the Septuagint it is not the color of the throne which is described as sapphire, but of the foundation, “the firmament” upon which rests the throne; and this agrees with Exodus 24:10, and Revelation 21:19. It is a very curious fact, pointed out by Delitzsch, that the ancients lacked color perception. No ancient language contains the word sky-blue. It was not until the Middle Ages that even the poets seem to have noticed that the sky was blue. The Hebrews alone seem to have discovered this and have expressed the thought beautifully with the help of the sapphire which is the more precious the deeper the blue. “Sapphire blue is the blue of the heaven; blue is the color of the atmosphere illumined by the sun, through which shine the dark depths of space; the color of the finite pervaded by the infinite; the color taken by that which is most heavenly as it comes down on the earthly, the color of the covenant between God and men. And blue passes almost universally as the color of fidelity… In biblical symbolism there is associated with blue the idea of the blue sky and with the blue sky the idea of the Godhead coming forth from its mysterious dwelling in the unseen world and graciously condescending to the creature.” Franz Delitzsch, Iris.