Previously Moses had sent his wife Zipporah and his two boys to live with his father-in-law Jethro, and now Jethro had taken them to catch up with Moses. When he got there, he noticed that Moses was spending all day judging the miscreants of the Israelites, and his caseload was killing him. Jethro advised that Moses delegate authority to minor judges, and Moses found this to be sound advice.
Exod.18:25-26 And Moses chose able men out of all Israel, and made them heads over the people, rulers of thousands, rulers of hundreds, rulers of fifties, and rulers of tens. And they judged the people at all seasons: the hard causes they brought unto Moses, but every small matter they judged themselves.
About two months after leaving Egypt the people came to the foot of Mount Sinai near the southern tip of the triangular peninsula. Moses went to the summit, where God announced that the Israelites had been chosen to be his priestly people. They would be a race of priests among the human race, participating in the ritual sacrifices, just as the Aaronic priesthood would be super-duper priests among the Israelites themselves who would perform the actual sacrifices. Moses went back down and told the people that’s what God had in mind. And he told them to get ready, and not have sex for three days, because on the third day God was going to land on Mount Sinai.
And mount Sinai was altogether on a smoke, because the LORD descended upon it in fire: and the smoke thereof ascended as the smoke of a furnace, and the whole mount quaked greatly.
But something had happened to God in the years since he used to walk in the Garden of Eden, or have a picnic with Abraham. He didn’t want the people to come too close to him anymore.
“Away, get thee down, and thou shalt come up, thou, and Aaron with thee: but let not the priests and the people break through to come up unto the LORD, lest he break forth upon them.”
Then God spoke to Moses the Ten Commandments (orally before committing them to stone):
1. Thou shalt have no other gods before me.
2. Thou shalt not make unto thee any graven image, or any likeness of any thing that is in heaven above, or that is in the earth beneath, or that is in the water under the earth. Thou shalt not bow down thyself to them, nor serve them.
3. Thou shalt not take the name of the LORD thy God in vain.
4. Remember the sabbath day, to keep it holy.
5. Honour thy father and thy mother: that thy days may be long upon the land which the LORD thy God giveth thee.
6. Thou shalt not kill.
7. Thou shalt not commit adultery.
8. Thou shalt not steal.
9. Thou shalt not bear false witness against thy neighbour.
10. Thou shalt not covet thy neighbour’s house, thou shalt not covet thy neighbour’s wife, nor his manservant, nor his maidservant, nor his ox, nor his ass, nor any thing that is thy neighbour’s.
Catholics traditionally use the restatement of the Ten Commandments in Deuteronomy chapter five as the template for the Ten Commandments which they teach Catechumens. It more clearly states the precept of not coveting another man’s wife as separate from not coveting his earthly goods. In order to maintain the number ten (because Exodus itself, in chapter 34, calls them the ten commandments), the first two commandments are merged into one, to read “Thou shalt have no other gods before me.”
Thus, Catholic catechisms often will not state the commandment against making graven images because it’s “covered” by saying have no other gods. Anti-Catholic Protestant sects such as the Seventh Day Adventists jump on that omission, claiming that Rome “changed the Bible” to allow devotions using Marian statuary, but that is not precisely true. Catholic Bibles retain the original text.