A more thorough explanation:

Res fit inempta (pronounced rays fit in-emp-tuh) is a Latin phrase that means "the object is regarded as unbought." This phrase was commonly used in ancient times to indicate that a sale had been cancelled or was no longer valid.

• John was going to buy a car, but when he found out it had been in a major accident, he decided not to. The seller then said, "Res fit inempta."
• Mary had agreed to sell her house to a buyer, but when the buyer couldn't secure financing, Mary said, "Res fit inempta."

These examples illustrate how the phrase can be used to indicate that a sale has been cancelled or is no longer valid. In both cases, the buyer was no longer interested in purchasing the object, and the seller used the phrase to indicate that the sale was off.