Makkot 9
MISHNA: [The false witnesses] divide the monetary payment but not the lashes. How is this? If they testified that a person was obligated to pay 200 zuz [a unit of currency] to his fellow and were then found to be false, they split the payment between them, but if they testified that a person was liable to forty lashes and were then found to be false, each [of the false witnesses] gets forty lashes.
GEMARA: From where is this known [that lashes can not be divided]? Abaye says, The word "rasha" (wicked person) is said by the laws of lashes (Deuteronomy 25, 2) and the word "rasha" is said by the laws of the death penalty (Numbers 35, 31). Just as there is no half of a death penalty, so too there is no half of lashes.
Rava says, We need to fulfill the requirement of (Deuteronomy 19, 19) "as he plotted to do his brother" and we can not. [He plotted to make his fellow liable a full forty lashes.] If so, than money should also [not be able to be divided]. Money combines, while lashes do not combine.
How is this? If they [the first set of witnesses] said, "We testify about this person, that he killed a man" [A second set of witnesses] said to them [the first set], "How can you testify, because the murderer or the victim was with us on that day in a different place?" They [the first set of witnesses] do not become zomemim. But if they [the second set of witnesses] said, "How can you testify, because you [the first set] were with us on that day in a different place?", then they [the first set] do become zomemim, and get executed on their [the second set's] words.
If others [a third set] came and were found to be zomemim [by the testimony of the second set], if others came and were found to be zomemim, even if there were one hundred [sets of witnesses], they all get executed. Rebbi Yehudah says, this group [the second set] is considered to be a 'plotting group' and no one gets executed besides for the first set of witnesses.
GEMARA: From ever do we know these words [that witnesses need to be personally disqualified to become zomemim]? Rav Ada says, The Torah says, (Deuteronomy 19: 18) "And behold, a false witness, he has testified falsely", [we derive that they doesn't become zomemim] until the body of the testimony [the witnesses themselves] get contradicted.
Rava says, If two [witnesses] come and say that they saw a person murder on the east east side of a building, and another two [witnesses] come and say that you [the first set] were with us on the west side of the building, then we see: If from standing at the west side of that building one can see to the east side of that building, they do not become zomemim, and if not then they do become zomemim.
And Rava also said, If two [witnesses] come and say, In we witnessed a murder in Sura [a town] on Sunday morning, and two [other witnesses] come and say that you [the first set] was with us on Sunday evening in Neharda [a town], we see if from morning to evening one can travel from Sura to Neharda, then they do become zomemim, but if not then they do not become zomemim.
And Rava said, If two [witnesses] come and say that they witnessed a murder on Sunday, and two [other witnesses] come and say that you [the first group] were with us on Sunday, but the murder did happen on Monday, and even if they [the second group of witnesses] say that the murder occurred on [the previous] Friday, they [the first group of witnesses] are executed [as zomemim] because at the time that they testified, the man [the accused] was not yet found guilty of death.
What is this [statement of Rava] coming to reach us? We [already] learned this in a mishna. "Therefore, if one of the [two groups that testified someone was liable for the death penalty] is found to be zomemim, he [the person they were testifying against] and they [the zomemim] are executed, and the second [group of witnesses, who haven't been found to be zomemim] is free.
He [Rava] needs to say it for its ending which talks about [after the] verdict having a different rule If two [witnesses] come and say that they witnessed the court issue a guilty verdict [for the death penalty] on Sunday, and two [other witnesses] come and say that you [the first group] were with us on Sunday, but the verdict was given on [the previous] Friday, and even if they [the second group of witnesses] say, the verdict occurred on Monday, they [the first group of witnesses] are not executed [as zomemim] because at the time that they testified, the man [the accused] was already found guilty of death.
And [we find a] similar [rule] with regard to paying a fine. If two [witnesses] come and say that a person stole [an animal], and slaughtered or sold it on Sunday, and two [other witnesses] come and say that you [the first group] were with us on Sunday, but the person did steal the animal and slaughter or sell it on Monday,
and even if they [the second group of witnesses] say that the person stole [the animal] and slaughtered or sold it on [the previous] Friday, they [the first group of witnesses] are found liable to pay [the intended fine as zomemim] because at the time that they testified, the man [the accused] was not yet found liable to the fine.
If two [witnesses] come and say, A person stole [an animal], slaughtered or sold it, and had a [guilty] verdict on Sunday, and two [other witnesses] come and say that you [the first group] were with us on Sunday, but the person did steal the animal, slaughter or sell it, and receive a [guilty] verdict on [the previous] Friday, and even if they [the second group of witnesses] say that the person stole [the animal], slaughtered or sold it, and received a [guilty] verdict on Monday, they [the first group of witnesses] are not found liable to pay [the intended fine as zomemim] because at the time that they testified, the man [the accused] was already found liable to the fine.