In the third month after the Israelites had left Egypt, on that very day, they came to the Desert of Sinai. They set out from Rephidim and entered the desert, where they camped in front of the mountain.
Then Moses went up to God, and the Lord called to him from the mountain, saying, "This is what you are to tell the house of Jacob, what you are to declare to the children of Israel: You have seen what I did to Egypt, how I carried you on eagles' wings and brought you to Myself. Now, if you fully obey My voice and keep My covenant, then out of all nations you will be My treasured possession. For the whole earth is Mine, but you will be for Me a kingdom of priests and a holy nation. These are the words you must speak to Israel."
So Moses went back and summoned the elders, setting before them all the words the Lord had commanded. The people all answered together, "We will do everything the Lord has spoken." Moses brought their reply back to the Lord.
The Lord said to Moses, "I am going to come to you in a dense cloud, so that the people will hear Me speaking with you and always put their trust in you." Then Moses told the Lord what the people had said.
The Lord said, "Go to the people and consecrate them today and tomorrow. Have them wash their clothes and be ready on the third day, for on that day the Lord will come down on Mount Sinai in the sight of all the people. Set limits around the mountain and warn them: Do not go up or touch the foot of it. Whoever touches the mountain must surely be put to death. He must be stoned or shot with arrows; no hand is to touch him. Whether man or animal, none shall live. Only when the ram's horn sounds a long blast may they go up the mountain."
Moses went down to the people, consecrated them, and they washed their clothes. He said to them, "Prepare yourselves for the third day. Abstain from sexual relations."
On the morning of the third day there was thunder and lightning, and a thick cloud covered the mountain. A loud trumpet blast sounded, and everyone in the camp trembled. Then Moses led the people out to meet God, and they stood at the foot of the mountain.
Mount Sinai was covered in smoke, for the Lord had descended on it in fire. The smoke rose like the smoke of a furnace, and the whole mountain shook violently. The trumpet grew louder and louder. Moses spoke, and God answered him with His voice.
The Lord came down to the top of Mount Sinai and called Moses up. So Moses went. The Lord said, "Go down and warn the people not to force their way through to see Me, or many will perish. Even the priests who approach the Lord must consecrate themselves, or I will break out against them."
Moses said, "The people cannot come up Mount Sinai, because You Yourself warned us to set limits around the mountain and set it apart as holy."
The Lord replied, "Go down and bring Aaron with you. But the priests and the people must not force their way through to come up to Me, or I will break out against them." So Moses went down to the people and gave them the Lord's message.