Shimon ben Shetach once had a single scheming witness — a zomem, one proven to have conspired to give false testimony — executed. Yehudah ben Tabbai was horrified. He said to Shimon: "May I not see the consolation if you did not spill innocent blood!"
Yehudah's objection was based on a precise legal principle. The Torah says "kill by witnesses" and "kill scheming witnesses." In both cases, the standard requires two. Just as conviction requires two witnesses, the punishment of scheming witnesses also requires two — both conspirators must be identified before either can be executed.
Shimon had executed a single scheming witness. But the law demands that both members of the conspiracy be caught and convicted together. Executing one without the other violated the Torah's insistence on the minimum of two.
This exchange between two of the greatest legal authorities of the Second Temple period reveals the stakes of judicial precision. Shimon ben Shetach was no fool — he was one of the most respected jurists of his era. But Yehudah ben Tabbai accused him of shedding innocent blood because the numerical requirement of two was not met. In Jewish law, even a proven liar — someone whose false testimony was exposed — cannot be punished unless the procedural requirements are satisfied exactly. The system's integrity depends on its rules being followed to the letter, even when the moral case for punishment seems clear.