Shabbat 102A

מתני׳ הזורק, ונזכר מאחר שיצתה מידו, קלטה אחר, קלטה כלב או שנשרפה ⁠— פטור. זרק לעשות חבורה, בין באדם ובין בבהמה, ונזכר עד שלא נעשית חבורה ⁠— פטור. זה הכלל: כל חייבי חטאות ⁠— אינן חייבין עד שתהא תחלתן וסופן שגגה. תחלתן שגגה וסופן זדון, תחילתן זדון וסופן שגגה ⁠— פטורין, עד שתהא תחילתן וסופן שגגה.

Mishnah: One who unwittingly throws an object from one domain to another or one who throws an object 4 cubits within the public domain, and after the object left his hand he remembered that he is in violation of a prohibition, if another caught it, or if a dog caught it, or if it was burned, he is exempt. Similarly, if one threw a rock on Shabbat to inflict a wound on a person or on an animal, for which one is liable to bring a sin-offering, and he remembered that he was in violation of a prohibition before the wound was inflicted, he is exempt. This is the principle: All who are liable to bring sin-offerings are only liable if the beginning of their action and the conclusion of their action are unwitting. However, if the beginning of one’s action was unwitting and the conclusion was intentional, as he became aware that he was in violation of a prohibition, or if the beginning of one’s action was intentional and the conclusion was unwitting, the individuals in both of these cases are exempt until both the beginning and the conclusion are unwitting.

גמ׳ הא נחה ⁠— חייב? והלא נזכר, ותנן: כל חייבי חטאות אינן חייבין עד שתהא תחלתן וסופן שגגה?! אמר רב כהנא: סיפא אתאן ללכתא ומתנא.

Talmud: We learned in the Mishnah that if one throws an object unwittingly and then remembers that he was in violation of a prohibition, he is exempt if the object did not come to rest on the ground. The Talmud infers: If the object comes to rest, he is liable. The Talmud asks: Why is he liable? Didn’t he remember the prohibition before it landed, and we learned in the Mishnah: All who are liable to bring sin-offerings are only liable if the beginning of their action and the conclusion of their action will be unwitting? If one remembered before the act was complete, he should be exempt. Rav Kahana said: With regard to the latter clause of the Mishnah, we have come to a special case of a bolt and a cord. The bolt is connected to a cord that one holds in his hand, which renders him capable of retrieving the bolt before it lands. Therefore, in a case where the beginning was unwitting and the conclusion was intentional, one is exempt because he is still capable of changing the outcome of the action. However, in the first clause of the Mishnah, once the object left his hand the action is irreversible, and therefore it is an action whose beginning and conclusion are unwitting.