On the first day of the third month after leaving Egypt, the people of Israel came to the desert of Sinai and Moses went up to the mountainside to meet God. The Lord called Moses and asked him to say to Jacob’s descendants, “You saw what I, the Lord, did to the Egyptians and how I brought you here to me. If you will obey and keep My covenant, you will be My own people. The whole earth is mine, but you will be My chosen people to serve me as priests.” Moses went down to the leaders of the people and told them everything that the Lord had commanded. All the people answered together, “We will do everything that the Lord has said.” The Lord said to Moses, “I will come to you in the thick cloud and the people will hear me speaking with you and will believe you from now on.”
Then the Lord said to Moses, “Go to the people and ask them to purify themselves for worship and be ready the day after tomorrow. On that day, I will come down to Mount Sinai so that all the people can see me. Mark a boundary around the mountain that the people must not cross. If the people and animals go up the mountain or get near it, then they must be put to death. When the trumpet is blown, the people will go up to the mountain.” Thunder, lightning and a thick cloud appeared on the morning of the third day, and the trumpet’s loud blast was heard. The people in the camp were afraid. Moses led them out to meet God at the foot of the mountain.
All of Mount Sinai was covered up in smoke like the smoke of a furnace, and the whole mountain trembled violently. The trumpet grew louder and louder. Moses spoke and God answered him with thunder. Moses and the Lord met on the top of Mount Sinai and the Lord said to Moses, “Go down and bring Aaron back with you. The priests and the people must not cross the boundary, otherwise, I will punish them.” Then Moses went down to the people and told them exactly what the Lord had said.