Exodus 24:16-18

ASV_Strongs(i)
  16 H3519 And the glory H3068 of Jehovah H7931 abode H2022 upon mount H5514 Sinai, H6051 and the cloud H3680 covered H8337 it six H3117 days: H7637 and the seventh H3117 day H7121 he called H4872 unto Moses H8432 out of the midst H6051 of the cloud.
  17 H4758 And the appearance H3519 of the glory H3068 of Jehovah H398 was like devouring H784 fire H7218 on the top H2022 of the mount H5869 in the eyes H1121 of the children H3478 of Israel.
  18 H4872 And Moses H935 entered H8432 into the midst H6051 of the cloud, H5927 and went up H2022 into the mount: H4872 and Moses H2022 was in the mount H705 forty H3117 days H705 and forty H3915 nights.