This is not an error of duplication. The full-fledged version of this Mitzvah are many and change for those who are learning the one/three chapter a day.
Negative Mitzvah 262
It is forbidden to neglect a wife's rights
Exodus 21:10 "He shall not diminish her food, her clothing, or rights of marriage"
When a master (or his son) marries his Jewish maidservant, he must treat her properly.
The Torah cautions him not to neglect her rights and provide her with all her needs. This Negative Mitzvah applies not only to a maidservant, but any Jewish wife.