Makkos 1:6-7
Makkos 1:6
False witnesses are not executed unless judgment against the accused has already been passed. The Sadducees claimed that false witnesses were only executed if the accused had already been put to death, based on Leviticus 24:18, “a life for a life.” The Sages replied that the Torah says, “You shall do to him as he sought to do to his brother” – from “sought to do” we infer that the one he falsely accused must still be alive. As to why it says “a life for a life,” this is because one might think that the false witnesses are liable to execution as soon as their testimony is received; “a life for a life” teaches us that they are only executed once the accused’s sentence has been passed.
Makkos 1:7
Deuteronomy 17:6 says, “By the testimony of two witnesses or three witnesses shall the one who is to die be put to death.” If the testimony of two witnesses is acceptable, why does the Torah need to tell us about three witnesses? This is in order to compare three witnesses to two: just as three witnesses can implicate two others as false witnesses, two witnesses can implicate three (i.e., three witnesses do not automatically “outvote” two). How do we know that two witnesses can implicate even 100 others? Because the Torah says “witnesses” (i.e., in any number). Rabbi Shimon says that just like two witnesses are only executed if they are both false witnesses, the same is true with three: they are only executed if all three of them are false witnesses. Once again, we know that this applies even to 100 witnesses because the Torah says “witnesses” (in any number). Rabbi Akiva says that the third witness is mentioned in order to treat him harshly by making his sentence the same as the first two (since only the testimony of the first two is actually necessary). If the Torah demands the same punishment of a person who follows sinners as it does from the sinners themselves, how much more so will God reward a person who follows those performing mitzvos the same as He does those actually performing the mitzvah!