Exodus 24:16-18 New English Translation (NET Bible)
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. 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. 18 Moses went into the cloud when he went up the mountain, and Moses was on the mountain forty days and forty nights.