10 -> 613 -> 2

Exodus 19 and Exodus 20:1-20 (NRSV)
At the third new moon after the Israelites had gone out of the land of Egypt, on that very day, they came into the wilderness of Sinai. 2They had journeyed from Rephidim, entered the wilderness of Sinai, and camped in the wilderness; Israel camped there in front of the mountain. 3Then Moses went up to God; the Lord called to him from the mountain, saying, ‘Thus you shall say to the house of Jacob, and tell the Israelites: 4You have seen what I did to the Egyptians, and how I bore you on eagles’ wings and brought you to myself. 5Now therefore, if you obey my voice and keep my covenant, you shall be my treasured possession out of all the peoples. Indeed, the whole earth is mine, 6but you shall be for me a priestly kingdom and a holy nation. These are the words that you shall speak to the Israelites.’
7 So Moses came, summoned the elders of the people, and set before them all these words that the Lord had commanded him. 8The people all answered as one: ‘Everything that the Lord has spoken we will do.’ Moses reported the words of the people to the Lord. 9Then the Lord 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 the Lord, 10the Lord said to Moses: ‘Go to the people and consecrate them today and tomorrow. Have them wash their clothes 11and prepare for the third day, because on the third day the Lord will come down upon Mount Sinai in the sight of all the people. 12You 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 touch the mountain shall be put to death. 13No 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.’ 14So Moses went down from the mountain to the people. He consecrated the people, and they washed their clothes. 15And he said to the people, ‘Prepare for the third day; do not go near a woman.’
16 On the morning of the third day there was thunder and lightning, as well as a thick cloud on the mountain, and a blast of a trumpet so loud that all the people who were in the camp trembled. 17Moses brought the people out of the camp to meet God. They took their stand at the foot of the mountain. 18Now Mount Sinai was wrapped in smoke, because the Lord had descended upon it in fire; the smoke went up like the smoke of a kiln, while the whole mountain shook violently. 19As the blast of the trumpet grew louder and louder, Moses would speak and God would answer him in thunder. 20When the Lord descended upon Mount Sinai, to the top of the mountain, the Lord summoned Moses to the top of the mountain, and Moses went up. 21Then the Lord said to Moses, ‘Go down and warn the people not to break through to the Lord to look; otherwise many of them will perish. 22Even the priests who approach the Lord must consecrate themselves or the Lord will break out against them.’ 23Moses said to the Lord, ‘The people are not permitted to come up to Mount Sinai; for you yourself warned us, saying, “Set limits around the mountain and keep it holy.” ’ 24The Lord said to him, ‘Go down, and come up bringing Aaron with you; but do not let either the priests or the people break through to come up to the Lord; otherwise he will break out against them.’ 25So Moses went down to the people and told them.
And God spoke all these words:
2 I am the Lord your God, who brought you out of the land of Egypt, out of the house of slavery; 3you shall have no other gods before* me.
4 You shall not make for yourself an idol, whether in the form of anything that is in heaven above, or that is on the earth beneath, or that is in the water under the earth. 5You shall not bow down to them or worship them; for I the Lord your God am a jealous God, punishing children for the iniquity of parents, to the third and the fourth generation of those who reject me, 6but showing steadfast love to the thousandth generation* of those who love me and keep my commandments.
7 You shall not make wrongful use of the name of the Lord your God, for the Lord will not acquit anyone who misuses his name.
8 Remember the sabbath day, and keep it holy. 9For six days you shall labour and do all your work. 10But the seventh day is a sabbath to the Lord your God; you shall not do any work—you, your son or your daughter, your male or female slave, your livestock, or the alien resident in your towns. 11For in six days the Lord made heaven and earth, the sea, and all that is in them, but rested the seventh day; therefore the Lord blessed the sabbath day and consecrated it.
12 Honour your father and your mother, so that your days may be long in the land that the Lord your God is giving you.
13 You shall not murder.*
14 You shall not commit adultery.
15 You shall not steal.
16 You shall not bear false witness against your neighbour.
17 You shall not covet your neighbour’s house; you shall not covet your neighbour’s wife, or male or female slave, or ox, or donkey, or anything that belongs to your neighbour.
18 When all the people witnessed the thunder and lightning, the sound of the trumpet, and the mountain smoking, they were afraid* and trembled and stood at a distance, 19and said to Moses, ‘You speak to us, and we will listen; but do not let God speak to us, or we will die.’ 20Moses said to the people, ‘Do not be afraid; for God has come only to test you and to put the fear of him upon you so that you do not sin.’ 
Our first reading for Sunday, October 2 is not all the above, but selected verses from Exodus chapter 20 (Exodus 20:1-4, 7-9, 12-20, in blue above), God giving Moses the Ten Commandments. There was a time in the church when the rubrics required the Decalogue to be read every Sunday morning as the beginning of the liturgy for Holy Communion. With the coming of the 1928 Book of Common Prayer, the requirement was eased to require reading it once a month. The 1979 prayer book sorts the Decalogue off by itself (BCP 317-318), and the rubrics now say that it may be said either during A Penitential Order (which some parishes use during Lent), or instead of the Summary of the Law in Holy Eucharist Rite One. 
It’s probably well to hear the Ten Commandments from time to time so that we at least know what they are. It’s a wonder there aren’t Twelve Commandments, twelve being a significant holy number of Israel. Maybe there originally were twelve and Moses talked the Lord down to just ten, we don’t know. Or maybe all twelve wouldn't fit on the tablets.
At the end of the Exodus reading for next Sunday, instead of cutting off where the Ten Commandments end at verse 17, it goes on with verses 18-20 -- about the thunder and lightening, and the trumpet, and the mountain smoking. That could be rather startling unless the hearer knows the scriptural setting. 
The scenario is described in Exodus chapter 19. Having been delivered from the Egyptians, the Israelites are now in the wilderness about three months. They’ve come to Mount Sinai, awesome mountain of God. Some have speculated that it’s an active volcano, but we don’t know. Regardless, it’s fearsome, and God is there. From now on, the children of Israel will be not merely a class of slaves and servants, and not tribes of wandering nomads, but a people. They will be the people of God, who here starts to give them laws for living. The rabbis say that there are 613 laws in Torah. These first ten are prime. Jesus summarizes them all as two: 

Jesus said, "The first commandments is this: Hear, O Israel:
The Lord your God is the only Lord. Love the Lord your
God with all your heart, with all your soul, with all your
mind, and with all your strength. The second is this: Love
your neighbor as yourself. There is no commandment
greater than these."   Mark 12:29-31

TW+