Exodus 24:

12 Then the Lord told Moses, “Go up to me on the mountain and stay[a] there. I’ll give you stone tablets with the instruction and law that I’ve written to teach the people.”[b]

13 So Moses got up, along with Joshua his servant, and went up on the mountain of God. 14 He told the elders, “Wait here for us until we return to you. Look, Aaron and Hur are with you, and whoever has a dispute, let him come to them.”

15 When Moses went up on the mountain, the cloud covered it. 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[c] 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.