"And if a man sells his daughter": A man may sell his daughter, but not his son. For it would follow (otherwise), viz.: If a father may sell his daughter, who (as an adult) is not sold (by beth-din) for stealing, how much more so may he sell his son, who (as an adult) is sold by beth-din for stealing! It is, therefore, written "And if a man sells his daughter." A man may sell his daughter, but not his son.