"And they shall judge the people with righteous judgment" [Shoftim 16:18]
A group of wicked individuals in the city of Vilna libeled one of the city's distinguished citizens. To ruin the man's reputation, they even hired false witnesses to substantiate their claim.
When word of the scandal reached the Vilna Gaon, he immediately suspected that the witnesses were hired to slander the man. He therefore requested to personally examine the "witnesses".
The witnesses appeared before the Gaon and related their testimony. The Gaon kept his eyes closed throughout their testimony and waited for them to finish. When they concluded, the Gaon rose to his feet and declared "They are false witnesses!"
The imposters, terrified by the Gaon's declaration, quickly admitted their guilt and revealed that they had been hired to deliver a false testimony.
The judges of the Beth Din were amazed. "How did Rebbeinu know that they were false witnesses?" they asked the Gaon.
"The answer lies in a Mishnah in Maseches Sanhedrin [5:4]" he replied.
"The Mishnah states that the judges first listen to the testimony of one witness. When the witness has concluded, the judges invite the second witness to testify. The Mishnah then states "If the words were found to correspond" then they are believed.
What does "if the words were found to correspond" mean? Either the testimonies match up or they do not; what need is there for the judges to figure out if the testimonies correspond?
"The reason" explained the Gaon, "is as follows: Every individual has his own style and approach when it comes to relating that which he has seen. Therefore, when judges hear two testimonies that differ slightly from one another, if they can find a way to reconcile them, the testimonies will be accepted by the Beth Din. For although the two witnesses expressed themselves in different manners, the two testimonies are one and the same. In fact, it is a sign that the witnesses are honest.
"However, when these witnesses testified before me" concluded the Gaon, "there were no discrepancies between their testimonies. If two people recount the same story, using the exact same words, it is a clear indication that they are false witnesses!"
Source: Rabbi Yisrael Bronstein
Source: Rabbi Yisrael Bronstein