Exodus 21:7

7 “If a man sells his daughter as a servant, she is not to go free as male servants do.

Read Exodus 21:7 Using Other Translations

And if a man sell his daughter to be a maidservant, she shall not go out as the menservants do.
"When a man sells his daughter as a slave, she shall not go out as the male slaves do.
“When a man sells his daughter as a slave, she will not be freed at the end of six years as the men are.