“Then Yahweh said to Moses, ‘I am going to come to you in a dense cloud, in order that the people may hear when I speak with you and so trust you ever after.’ When Moses had told the words of the people to Yahweh, Yahweh said to Moses, ‘Go to the people and consecrate them today and tomorrow. Have them wash their clothes and prepare for the third day, because on the third day Yahweh will come down upon Mount Sinai in the sight of all the people. You shall set limits for the people all around, saying, ‘Be careful not to go up the mountain or to touch the edge of it. Any who touches the mountain shall be put to death. No hand shall touch them, but they shall be stoned or shot with arrows. Whether animal or human being, they shall not live. When the trumpet sounds a long blast, they may go up on the mountain.’ So Moses went down from the mountain to the people. He consecrated the people. They washed their clothes. He said to the people, ‘Prepare for the third day. Do not go near a woman.’”
Yahweh told Moses that he was going to come in a dense cloud. The people could hear him but not see him. Moses was told to consecrate the people and have them wash their clothes to prepare for the third day, when Yahweh would come down upon Mount Sinai. They have certain limitations and restrictions. They could not go up the mountain or to touch it. The men could not touch women. If they touched the mountain they would be put to death. No hand would touch them, but they would be stoned or shot with arrows. However, when the trumpet sounded a long blast, they could go up the mountain. Moses conveyed this to the people. Yahweh has very clear strict regulations about purifying themselves and if they failed to follow them, they would die. Notice that the killing by stoning and arrows meant that you did not kill with your own hands, but used materials to kill them.