Exodus 24:18 in the World English Bible
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.
Context
17 And the sight of the glory of the LORD was like devouring fire on the top of the mount in the eyes of the children of Israel.
18 And Moses went into the midst of the cloud, and gat him up into the mount: and Moses was in the mount forty days and forty nights.