Exodus 21:15

And he that smiteth his father, or his mother, shall be surely put to death.

Exodus 21:15 belongs to the additional statutes and judgments, the specific instruction God gave privately to Moses for him to communicate to Israel to regulate how they dealt with one another. It was not spoken aloud with the Decalogue but delivered to Moses alone, who was to convey it to the people. These additional precepts were given because the minds of the people, blinded and debased by slavery, were not prepared to appreciate fully the far-reaching principles of God's ten precepts.

It was given to illustrate and apply the precepts of the Ten Commandments, that the obligations of the Decalogue might be more fully understood and enforced. It is one of the specific judgments that spell out how God's commandments apply to conduct toward one another. These detailed directions guard against injustice and guide dealings between people, while guarding the sacredness of the Ten Commandments and leaving no room for confusion about what they require.

The verse makes striking either father or mother — rebellion against parental authority — a crime punishable by death. In this it shows that God's law guards family relationships with an exalted requirement. Its observance is plainly enjoined, for these laws were to be read carefully and strictly obeyed. Keeping God's law in truth and righteousness means obeying every command.