"God spoke all these words, saying: I am God your Lord, who brought you out of Egypt, from the place of slavery.
According to the Bible itself, the commandments represent the solemn utterances of God on Mount Sinai (sometimes called Mount Horeb), directly revealed by God to Moses and then by Moses to the people of Israel in the third month after their Exodus from Egypt.
The Israelites are said to have seen manifestations of divine power marked by thunder and lightning and thick smoke (Exodus 19):
"...God said to Moses, 'I will come to you in a thick cloud, so that all the people will hear when I speak to you. They will then believe in you forever.'...The third day arrived. There was thunder and lightning in the morning, with a heavy cloud on the mountain, and an extremely loud blast of a ram's horn.
The people in the camp trembled. Moses led the people out of the camp toward the Divine Presence. They stood transfixed at the foot of the mountain. Mount Sinai was all in smoke because of the Presence that had come down on it. God was in the fire, and its smoke went up like the smoke of a lime kiln.
The entire mountain trembled violently. There was the sound of a ram's horn, increasing in volume to a great degree. Moses spoke, and God replied with a Voice. God came down on Mount Sinai, to the peak of the mountain. He summoned Moses to the mountain peak, and Moses climbed up...Moses went down to the people and conveyed this to them."  God's name God had already revealed his true name to Moses in the past (Exodus 6). Exodus 20 / Deuteronomy 5
The Commands of God
|Do not have any other gods before Me.|
|Do not represent [such] gods by any carved statue or picture of anything in the heaven above, on the earth below, or in the water below the land.|
|Do not bow down to [such gods] or worship them. I am God your Lord, a God who demands exclusive worship.|
|Where My enemies are concerned, I keep in mind the sin of the fathers for [their] descendants, to the third and fourth [generation]. But for those who love Me and keep My commandments, I show love for thousands [of generations].|
|Do not take the name of God your Lord in vain. God will not allow the one who takes His name in vain to go unpunished.|
|Remember the Sabbath to keep it holy. You can work during the six weekdays and do all your tasks. But Saturday is the Sabbath to God your Lord. Do not do anything that constitutes work. [This includes] you, your son, your daughter, your slave, your maid, your animal, and the foreigner in your gates. It was during the six weekdays that God made the heaven, the earth, the sea, and all that is in them, but he rested on Saturday. God therefore blessed the Sabbath day and made it holy.|
|Honor your father and mother. You will then live long on the land that God your Lord is giving you.|
|Do not commit murder.|
|Do not commit adultery.|
|Do not steal.|
|Do not testify as a false witness against your neighbor.|
|Do not be envious of your neighbor's house.|
|Do not be envious of your neighbor's wife, his slave, his maid, his ox, his donkey, or anything else that is your neighbor's."|