They saw the God of Israel - The seventy elders, who were representatives of the whole congregation, were chosen to witness the manifestation of God, that they might be satisfied of the truth of the revelation which he had made of himself and of his will; and on this occasion it was necessary that the people also should be favored with a sight of the glory of God; see Exodus 20:18. Thus the certainty of the revelation was established by many witnesses, and by those especially of the most competent kind.
A paved work of a sapphire stone - Or sapphire brick-work. I suppose that something of the Musive or Mosaic pavement is here intended; floors most curiously inlaid with variously coloured stones or small square tiles, disposed in a great variety of ornamental forms. Many of these remain in different countries to the present day. The Romans were particularly fond of them, and left monuments of their taste and ingenuity in pavements of this kind, in most countries where they established their dominion. Some very fine specimens are found in different parts of Britain.
Sapphire is a precious stone of a fine blue color, next in hardness to the diamond. The ruby is considered by most mineralogists of the same genus; so is also the topaz: hence we cannot say that the sapphire is only of a blue color; it is blue, red, or yellow, as it may be called sapphire, ruby, or topaz; and some of them are blue or green, according to the light in which they are held; and some white. A very large specimen of such a one is now before me. The ancient oriental sapphire is supposed to have been the same with the lapis lazuli. Supposing that these different kinds of sapphires are here intended, how glorious must a pavement be, constituted of polished stones of this sort, perfectly transparent, with an effulgence of heavenly splendor poured out upon them! The red, the blue, the green, and the yellow, arranged by the wisdom of God, into the most beautiful emblematic representations, and the whole body of heaven in its clearness shining upon them, must have made a most glorious appearance. As the Divine glory appeared above the mount, it is reasonable to suppose that the Israelites saw the sapphire pavement over their heads, as it might have occupied a space in the atmosphere equal in extent to the base of the mountain; and being transparent, the intense brightness shining upon it must have greatly heightened the effect.
It is necessary farther to observe that all this must have been only an appearance, unconnected with any personal similitude; for this Moses expressly asserts, Deuteronomy 4:15. And though the feet are here mentioned, this can only be understood of the sapphirine basis or pavement, on which this celestial and indescribable glory of the Lord appeared. There is a similar description of the glory of the Lord in the Book of Revelation, Revelation 4:3; : "And he who sat [upon the throne] was to look upon like a jasper and a sardine stone; and there was a rainbow round about the throne, in sight like unto an emerald." In neither of these appearances was there any similitude or likeness of any thing in heaven, earth, or sea. Thus God took care to preserve them from all incentives to idolatry, while he gave them the fullest proofs of his being. In Scheuchzer's Physica Sacra, among his numerous fine engravings, there is one of this glorious manifestation, which cannot be too severely reprehended. The Supreme Being is represented as an old man, sitting on a throne, encompassed with glory, having a crown on his head, and a scepter in his hand, the people prostrate in adoration at the foot of the piece. A print of this kind should be considered as utterly improper, if not blasphemous.