Exodus 24:10

24:10 and they saw the God of Israel. Under his feet there was something like a pavement made of sapphire, clear like the sky itself.

Exodus 24:16-17

24:16 The glory of the Lord resided on Mount Sinai, and the cloud covered it for six days. On the seventh day he called to Moses from within the cloud. 24:17 Now the appearance of the glory of the Lord was like a devouring fire on the top of the mountain in plain view of the people.