15 And Moses went up into the mount, and the cloud covered the mount.
Exodus 24:15 Cross References - JPS_ASV_Byz
Exodus 19:9
9 And the LORD said unto Moses: 'Lo, I come unto thee in a thick cloud, that the people may hear when I speak with thee, and may also believe thee for ever.' And Moses told the words of the people unto the LORD.
Exodus 19:16
16 And it came to pass on the third day, when it was morning, that there were thunders and lightnings and a thick cloud upon the mount, and the voice of a horn exceeding loud; and all the people that were in the camp trembled.
2 Chronicles 6:1
1 Then spoke Solomon: The LORD hath said that He would dwell in the thick darkness.
Matthew 17:5
5 While he was yet speaking, behold, a bright cloud overshadowed them; and behold, a voice out of the cloud, saying, This is my beloved Son, in whom I am well pleased, hear ye him.