They saw a dark cloud above the mountain while Moses talked with God...
The Hebrew name of that mountain, recorded in the Torah, is "SEE - nye". The word came into English translations of the Bible as "Sinai". The entire inverted-triangular peninsula between Egypt and Israel is known as the "Sinai" peninsula, and there is a tourist-frequented monastery in the mid-south of the peninsula on a mountain identified by some as the mountain associated with the ten commandments. But the fact is that the mountain has not been identified with any certainty.
When Moses came down from mount Sinai , he was very angry with the people, he then threw the two tablets of stone and it broke.
When Moses came down from Mount Sinai with the Ten Commandments, no one died. However, in a separate incident, when Moses was on Mount Sinai receiving the commandments, some Israelites worshiped a golden calf instead and about 3,000 people died as a result of their disobedience.
Moses came down from mount Sinai with the two tablets of stone, that had the ten commandments.
When God spoke to Moses in from the burning bush, it was on land, he went to mount Sinai for the ten commandments.
When Moses came down from Mount Sinai, his face emanated rays that reflected God's glory.
It was Moses, as Moses came down from the Mount of Sinai after meeting God and got the ten commandments, his face was glowing.
Moses climbed Mount Sinai to receive the Ten Commandments from God after the Israelites had left Egypt. Abraham moved to Canaan many years before Moses, as part of God's promise to make his descendants a great nation.
3-months after leaving Egypt, Moses and the Israelis came to Mount Sinai. Moses received the "Ten Commandants" and the plans for the earthly tabernacle. They were in the wilderness.
He got angry as the people were worshiping a golden calf, and broke the first commandment.
The answer to this can be found in Exodus 32. After receiving from God the tablets into which were carved the Ten Commandments, Moses came down from Mount Sinai. He found the Israelites worshipping an idol, since the people had given up on Moses ever returning. Moses threw the tablets to the ground and crushed them. He then mixed the crushed tablets with water and made the Israelites drink down the resulting mixture.
Moses wore a veil after he came down from talking with God on Mount Sinai because his face was glowing from having been so close to God's glory. The people were disturbed by his glowing face and asked him to wear a veil until the glow faded. You can read about it in Exodus 34:29-35.