Shabbat 18A

השמש. אמר רבן שמעון בן גמליאל: נוהגין היו בית אבא שהיו נותנין כלי לבן לכובס גוי שלשה ימים קודם לשבת. ושוין אלו ואלו, שטוענין קורת בית הבד ועגולי הגת.

the sun, i.e., as long as the sun is shining on Friday. Rabban Shimon ben Gamliel said: The ancestral house of my father, the dynasty of Nesi’im from the house of Hillel, was accustomed to give its white clothes to a non-Jew launderer no fewer than 3 days before Shabbat. And, however, these, Beit Shammai, and those, Beit Hillel, agree that, ab initio, one may load the beam of the olive press on the olives on Friday while it is still day, so that the oil will continue to be squeezed out of the olives on Shabbat. So too, one may load the circular wine press to accelerate the process of producing wine from the grapes.

גמ׳ מאן תנא נתינת מים לדיו זו היא שרייתן? אמר רב יוסף: רבי היא. דתניא: אחד נותן את הקמח ואחד נותן את המים ⁠— האחרון חייב, דברי רבי. רבי יוסי אומר: אינו חייב עד שיגבל.

Talmud: Before clarifying the matters themselves, the Talmud seeks to determine: Who is the tanna who holds that merely adding water to ink without any additional action constitutes its soaking, and one is liable for doing so on Shabbat, as he performed an act of kneading, one of the primary categories of labor? Rav Yosef said: It is the opinion of R' Yehuda HaNasi. As it was taught in a baraita: In a case where one person adds the flour and another one adds the water into one vessel, the latter one is liable for kneading the dough, which is a prohibited labor on Shabbat, even though he did not actually knead the dough; that is the statement of R' Yehuda HaNasi. R' Yosei says: He is not liable for the prohibited labor of kneading until he actually kneads the dough. According to R' Yehuda HaNasi, merely soaking the dough in water is considered a prohibited labor.