Exactly two months after the Israelites left Egypt, they arrived in the wilderness of Sinai.
References for Exodus 19:1
After breaking camp at Rephidim, they came to the wilderness of Sinai and set up camp there at the base of Mount Sinai.
Then Moses climbed the mountain to appear before God. The LORD called to him from the mountain and said, “Give these instructions to the family of Jacob; announce it to the descendants of Israel:
‘You have seen what I did to the Egyptians. You know how I carried you on eagles’ wings and brought you to myself.
Now if you will obey me and keep my covenant, you will be my own special treasure from among all the peoples on earth; for all the earth belongs to me.
And you will be my kingdom of priests, my holy nation.’ This is the message you must give to the people of Israel.”
So Moses returned from the mountain and called together the elders of the people and told them everything the LORD had commanded him.
And all the people responded together, “We will do everything the LORD has commanded.” So Moses brought the people’s answer back to the LORD .
Then the LORD said to Moses, “I will come to you in a thick cloud, Moses, so the people themselves can hear me when I speak with you. Then they will always trust you.” Moses told the LORD what the people had said.
Then the LORD told Moses, “Go down and prepare the people for my arrival. Consecrate them today and tomorrow, and have them wash their clothing.
Be sure they are ready on the third day, for on that day the LORD will come down on Mount Sinai as all the people watch.
Mark off a boundary all around the mountain. Warn the people, ‘Be careful! Do not go up on the mountain or even touch its boundaries. Anyone who touches the mountain will certainly be put to death.
No hand may touch the person or animal that crosses the boundary; instead, stone them or shoot them with arrows. They must be put to death.’ However, when the ram’s horn sounds a long blast, then the people may go up on the mountain. ”
References for Exodus 19:13
So Moses went down to the people. He consecrated them for worship, and they washed their clothes.
He told them, “Get ready for the third day, and until then abstain from having sexual intercourse.”
On the morning of the third day, thunder roared and lightning flashed, and a dense cloud came down on the mountain. There was a long, loud blast from a ram’s horn, and all the people trembled.
Moses led them out from the camp to meet with God, and they stood at the foot of the mountain.
All of Mount Sinai was covered with smoke because the LORD had descended on it in the form of fire. The smoke billowed into the sky like smoke from a brick kiln, and the whole mountain shook violently.
As the blast of the ram’s horn grew louder and louder, Moses spoke, and God thundered his reply.
The LORD came down on the top of Mount Sinai and called Moses to the top of the mountain. So Moses climbed the mountain.
Then the LORD told Moses, “Go back down and warn the people not to break through the boundaries to see the LORD, or they will die.
Even the priests who regularly come near to the LORD must purify themselves so that the LORD does not break out and destroy them.”
“But LORD,” Moses protested, “the people cannot come up to Mount Sinai. You already warned us. You told me, ‘Mark off a boundary all around the mountain to set it apart as holy.’”
But the LORD said, “Go down and bring Aaron back up with you. In the meantime, do not let the priests or the people break through to approach the LORD, or he will break out and destroy them.”
So Moses went down to the people and told them what the LORD had said.