Exodus 19:17-19

Young's Literal Translation

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;

¹⁹ and the sound of the trumpet is going on, and very strong; Moses speaketh, and God doth answer him with a voice.