Shabbos Daf 121 שבת דַף 121

The next Mishnah states that one may not say to a gentile that has come to extinguish a fire, “Extinguish it,” but he does not have to tell him, “Do not extinguish it,” because the gentile’s shevisa, (his resting on Shabbos), is not the Jew’s responsibility. However, one may not allow a Jewish child to extinguish it because the child’s shevisa is his responsibility.

Rebbe Yochanan clarifies that the Mishnah forbids allowing a child to extinguish a fire specifically since the child wants to extinguish the fire for his father, but in a case where the child is acting for himself, such as in a case of him eating neveilah, one is not mandated to stop the child. The Gemara asks, why then is it permitted to let a gentile extinguish a fire, since he is acting on behalf of the Jew?

The Gemara answers that נכרי לדעתיה דנפשיה עביד – that a gentile always acts in his own self-interest. 

The next Mishnah teaches that one may invert a bowl over  צואה של קטן, a child’s feces.

Rebbe Avin was teaching his son that the Mishnah means that one may cover child’s feces in order that a child will not dirty himself from it. Rav Chanan  bar Rava corrected Rebbe Avin, and said that a child’s feces is not muktzeh since dogs nibble at it, and it is therefore considered muchan, (prepared) for their consumption. Therefore, it does not need to be covered, since it can be moved. Rather, said Rav Chanan, the Mishnah is teaching that one may invert a bowl over chicken feces so that a child will not get himself dirty from it. Chicken feces is muktzeh since it is not fit for dogs, and therefore it cannot be moved.

A teacher of Baraisos taught in the presence of Rav bar Rav Huna that if one kills poisonous snakes or scorpions on Shabbos, אין רוח חסידים נוחה הימנו – Chassidim  are not pleased with him, (for killing a creature on Shabbos unnecessarily).

Rava bar Rav Huna responded that אין רוח חכמים נוחה מהם – The Sages are not pleased with those chassidim. Rashi explains that even though that those creatures did not pose a current direct danger, they will present a danger when they are angry.

The Gemara notes that Rav Huna disagrees with his son, Rava, for he once saw a person killing a bee on Shabbos and said to him, “Have you finished them all off?” Rashi explains that Rav Huna questioned what had been accomplished, as there are still more bees. This shows that Rav Huna does not allow killing bees indiscriminately.