Sanhedrin 78A

ואי לאו כחו הוא ⁠– תיזיל לתחת. אלא, כח כחוש הוא.

Rav Pappa answered: And were it not for the force of his action, the stone would go down and not to the side. Rather, although it is a weak force, the force of his action is a partial cause of the damage caused by the stone going to the side; therefore, he is liable.

תנו רבנן: הכוהו עשרה בני אדם בעשרה מקלות ומת, בין בבת אחת, בין בזה אחר זה ⁠– פטורין. רבי יהודה בן בתירא אומר: בזה אחר זה, האחרון חייב, מפני שקירב את מיתתו.

A baraita states: If 10 people struck an individual with 10 sticks and as a result of the beating he died, whether they beat him simultaneously, or whether they beat him one after the other, they are exempt from liability for killing him, as two people are not liable for an action that they performed together. R' Yehuda ben Beteira says: If they struck him one after the other, the one who struck him last is liable, because he hastened his death.

אמר רבי יוחנן: ושניהם מקרא אחד דרשו, ״ואיש כי יכה כל נפש אדם״. רבנן סברי: ״כל נפש״⁠ – עד דאיכא כל נפש, ורבי יהודה בן בתירא סבר: ״כל נפש״⁠ – כל דהוא נפש.

R' Yoḥanan says: And both Rabbis, i.e., the first tanna and R' Yehuda ben Beteira, interpreted the same verse in drawing their halakhic conclusion. The verse states: “And a man who strikes any soul mortally, he should be put to death” (Leviticus 24:17). The Rabbis hold that “any soul” means that one is liable for murder only when there is an entire soul, i.e., when the murderer alone is responsible for taking the entire life of the victim. And R' Yehuda ben Beteira holds that “any soul” means that one is liable for murder for taking any soul, even if the victim had already been beaten and was close to death.

אמר רבא: הכל מודים בהורג את הטריפה שהוא פטור, בגוסס בידי שמים שהוא חייב. לא נחלקו אלא בגוסס בידי אדם. מר מדמי ליה לטריפה, ומר מדמי ליה לגוסס בידי שמים.

§ Rava says: All concede that in the case of one who kills one who has a wound that will cause him to die within 12 months [tereifa] he is exempt from liability, as in a certain sense the legal status of the victim is that of a dead person. All concede in a case where one kills an individual dying from an illness caused at the hand of Heaven that he is liable, as no other individual took action contributing to his death, and the murderer alone took his remaining soul. They disagree only in a case where one kills an individual dying from injury caused at the hand of a person. One Sage, the Rabbis, likens this case to the case of a tereifa, and therefore rules that the one who kills him is exempt. And one Sage, R' Yehuda, likens this case to the case of an individual dying from an illness caused at the hand of Heaven, and therefore rules that the one who kills him is liable.