פירוש על קידושין 55:6

Rava adjusts the resolution slightly—he must swear that he was not sold as a Hebrew slave. Being a Hebrew slave is not so ignominious because it does not affect one’s language.

The problem with this is that saying that someone else is your Hebrew slave is essentially saying that he owes you money. A Hebrew slave is like an indentured servant. This is not a good example, therefore, of an oath being overextended. It is a simple extension of an oath from one issue of money to another.

The Talmud resolves by saying that to Rava this is not simply a monetary claim. To Rava, the master owns the Hebrew slave and therefore this is a further extension of the oath.