fire and lightning? trumpet and smoke?

What fire and lightning, trumpet and smoke?

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Exodus 20:1-4, 7-9, 12-20
God spoke all these words:
I am the Lord your God, who brought you out of the land of Egypt, out of the house of slavery; you shall have no other gods before me.
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.
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.
Remember the sabbath day, and keep it holy. For six days you shall labour and do all your work.
Honor your father and your mother, so that your days may be long in the land that the Lord your God is giving you.
You shall not murder.
You shall not commit adultery.
You shall not steal.
You shall not bear false witness against your neighbor.
You shall not covet your neighbor’s house; you shall not covet your neighbor’s wife, or male or female slave, or ox, or donkey, or anything that belongs to your neighbor.
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, and said to Moses, “You speak to us, and we will listen; but do not let God speak to us, or we will die.” Moses 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.”
In the Revised Common Lectionary (“common” in that it is used by several worship communities, Christian denominations including our Episcopal Church) this reading from Exodus is prescribed for congregations who are using Track One (in Track One the OT reading and its responsive psalm read stories consecutively through the Old Testament; in Track Two the OT reading and its responsive psalm are related in some way to the Gospel reading for the Sunday). The readings may raise questions in one’s mind, for example, “Fire and lightning, trumpet and smoke, what fire and lightning …?” because the lectionary framers didn’t include enough of the story to let us know what’s going on. So for self-enlightenment, one turns pages back to get the rest of the story. In this case, going from Exodus 20 back and reading Exodus 19, which picks up the exodus adventure “on 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” where begins the terrifying excitement of encountering God’s holy mountain.
The story is a quick, interesting and fun read that will only take a couple minutes to lay foundation and become part of the picture. https://www.biblegateway.com/passage/?search=Exodus+19&version=NRSV . On Sunday, Linda and I will be visiting a nearby town to fill in for a priest who is away, but for a Sunday school class this coming Sunday morning, that is part of what I would do. 
DThos+