On the way to Canaan, at Mount Sinai (or Horeb), Moses receives the first foundational divine laws we know as the Ten Commandments. These are deemed the most essential ethical principles of both Judaism and Christianity; it is worth halting the story to review them.
Everyone agrees there are ten, but not every compilation of the texts at Exodus 20: 2-17 and Deuteronomy 5:6-21 breaks them up the same way.
The first three commandments (or two, in some counts) are about the relationship with God. The first is a call for total and primary allegiance to Adonai (Hebrew for “Lord”) above all other gods, without the distraction of graven images. Failure to do so is subject to “visiting the iniquity” of those who forsake the jealous God, while faithful obedience is rewarded by “steadfast love.”
Then there’s the demand to respect God's name, which we discussed earlier in the power of naming. In some circles this is interpreted as a prohibition on writing the holy name (YHVH, rendered in modern translations as Yahweh or Jehovah to fill in the vowels that biblical Hebrew didn’t use).
However, it is probably more aptly seen as a command not to think you can have God in your power, in your pocket, or on your side); in the biblical understanding, to name something was to have power and control over it. Note how Adam is given dominion over all creatures and told to name them; this is not entirely dissimilar to parents’ power in naming their child. Also implicit in not using the name in vain is the prohibition against perjury, or stating a lie when calling upon God as a witness—the essence of an oath.
Last in these rules concerning the relationship with God is making holy (or setting apart) "the Sabbath" or "the Lord's Day." The Sabbath, or Saturday, was understood as the seventh day, when God rested after creation. Christian sabbatarianism shifted the day to Sunday, the day the resurrection of Jesus is commemorated. This has been variously interpreted as having something to do with going to church or to the synagogue, but in the biblical text neither is explicitly involved.
The remaining seven (or eight) commands are about the relations between humans, starting with that of child and parent. The “honor” due a parent is not defined. Instead, a good-for-you sort of reciprocity is implied: the child who honors a parent will live long and in turn be honored as a parent. In various other biblical, rabbinical and ecclesiastical takes, there is a parallelism seen in honoring one’s biological parents and honoring God, the ultimate parent of all.
The imperative against killing is specifically against murder (retsach in Hebrew). The word is used in reference to what was done to Abel, whose brother Cain slew him out of jealousy (Genesis 4:8). It also appears when Moses slays an Egyptian in reprisal for killing a Hebrew slave (Exodus 2:11-12). However, it is not used biblically for killing in war and the Bible draws a clear distinction that exempts killing as the due consequence of a crime; indeed, capital punishment is biblically mandated for a variety of wrongdoings, including murder.
Adultery, the subject of the next commandment, meant sexual relations between a married woman and a man not her husband—both before Sinai (Gen. 12:17 and 20:3) and later under Mosaic law. The prohibition concerned abusing property rights in two respects: first, by taking from the husband his wife, his alone to enjoy sexually; secondly, by introducing the possibility of the husband’s inheritance ending up in the hands of a child sired by another man, effectively stealing it from the husband’s heirs by blood.
Catholic moral theology expanded adultery to cover all sex outside sacramental matrimony; in the Protestant view, it generally means sexual relations in which at least one participant, male or female, is married to someone else.
Christian interpretations notwithstanding, the property element in the ancient biblical understanding of adultery is confirmed in the very next command against stealing, which was also understood to include stealing the freedom of another Hebrew for personal or commercial purposes.
Next comes the command barring false witness against a neighbor, which calls out once again the prohibition against perjury; neighbor means anyone with whom a Hebrew might come in contact.
The two (or one) commands against coveting are the only ethical principles concerning relations between people that prohibit a certain kind of thought, emotion or disposition. There are arguments as to whether the word “covet” is an apt translation. The Hebrew is chamad, rendered in English also as “lust” and “strong desire.” The medieval Spanish rabbi Maimonides offered the prevailing widespread interpretation that the prohibition keeps the believer a safe distance away from theft, adultery and murder.
At this point, I cannot help but repeat a biblical study joke that unites the two verses, whether counted as one commandment or two. One prohibits coveting one’s neighbor’s house, manservant or maidservant, or his ox or ass. The other prohibits coveting the neighbor's wife. Some wags suggest that there is no difference between a neighbor’s ass and a neighbor’s wife.
Rounding up with a little more seriousness, it should be understood that these commands were presented as the “quid” of the quid pro quo between God as liberator from Egypt and the Hebrew people: I took you out of bondage, now these are my rules.
These were not understood by the ancient Hebrews—or by Jews today—as universal moral rules. In the Jewish understanding, Jews are bound to the Ten Commandments, or Decalogue, along with 603 other laws in the Torah, including some of considerably lesser moral significance, such as dietary laws.
Gentiles, in effect almost all humanity, are only bound to the Seven Laws of Noah (also known as Noahide Law), which combine the six ordinances given by God to Adam at Eden (Genesis 2:16-25) plus one added in the covenant with Noah after the Flood (Genesis 9). They prohibit idolatry, murder, theft, sexual immorality, blasphemy and eating flesh taken from an animal while it is still alive; in addition, the law commands the establishment and maintenance of courts to provide legal redress for wrongdoing.
In the Christian understanding, the Ten Commandments were subsumed into faith in Jesus Christ, who professed not to abolish the Law of Moses, but to fulfill it. Granted, as we shall see, the Christian faith is not at heart a matter of rules.