Exodus 24:15-18

24:15 Moses went up on the mountain, and the cloud covered the mountain.

24:16 The LORD’s glory settled on Mount Sinai, and the cloud covered it six days. The seventh day he called to Moses out of the middle of the cloud.

24:17 The appearance of the LORD’s glory was like devouring fire on the top of the mountain in the eyes of the children of Israel.

24:18 Moses entered into the middle of the cloud, and went up on the mountain; and Moses was on the mountain forty days and forty nights.