Exodus 19:18-20 World English Bible (WEB)
18 All of Mount Sinai smoked, because Yahweh descended on it in fire; and its smoke ascended like the smoke of a furnace, and the whole mountain quaked greatly. 19 When the sound of the trumpet grew louder and louder, Moses spoke, and God answered him by a voice. 20 Yahweh came down on Mount Sinai, to the top of the mountain. Yahweh called Moses to the top of the mountain, and Moses went up.