Exodus 19:18-20

Young's Literal Translation

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.

²⁰ And Jehovah cometh down on mount Sinai, unto the top of the mount, and Jehovah calleth for Moses unto the top of the mount, and Moses goeth up.