What is the ruling regarding the forfeiture of the right of preemption (Shuf'ah) when the claimant is informed of a sale and affirms that information?

Primary text

The right of preemption is voided if the claimant is informed of the sale and affirms that information, regardless of whether the informer is someone whose testimony is generally accepted or not. This is because knowledge can be established through the report of someone whose testimony is not accepted, due to corroborating signs indicating the truthfulness of the report.