Exodus 19:16-18

Young's Literal Translation

¹⁶ And it cometh to pass, on the third day, while it is morning, that there are voices, and lightnings, and a heavy cloud, on the mount, and the sound of a trumpet very strong; and all the people who [are] in the camp do tremble.

¹⁷ And Moses bringeth out the people to meet God from the camp, and they station themselves at the lower part of the mount,

¹⁸ and mount Sinai [is] wholly a smoke from the presence of Jehovah, who hath come down on it in fire, and its smoke goeth up as smoke of the furnace, and the whole mount trembleth exceedingly;