Exodus 19:17

Moses went down from the mountain to the people, and sanctified the people; and they washed their clothes.

He said to the people, “Be ready by the third day. Don’t have sexual relations with a woman.”

On the third day, when it was morning, there were thunders and lightnings, and a thick cloud on the mountain, and the sound of an exceedingly loud trumpet; and all the people who were in the camp trembled.

All of Mount Sinai smoked, because the LORD descended on it in fire; and its smoke ascended like the smoke of a furnace, and the whole mountain quaked greatly.

When the sound of the trumpet grew louder and louder, Moses spoke, and God answered him by a voice.

The LORD came down on Mount Sinai, to the top of the mountain. The LORD called Moses to the top of the mountain, and Moses went up.