Exodus 24:16-18 International Standard Version (ISV)
16 The glory of the Lord settled on Mount Sinai, and the cloud covered it for six days. Then on the seventh day he called to Moses from within the cloud. 17 To the Israelis[a] the appearance of the glory of the Lord was like a consuming fire on top of the mountain. 18 When Moses went up on the mountain, he went into the center of the cloud and was on the mountain for 40 days and 40 nights.