“It was on the third day, when they were in pain, that the two sons of Jacob, Simeon and Levi, Dina's brothers, each man took his sword, and came upon the city confidently, and killed all the males” (Genesis 34:25). “It was on the third day, when they were in pain” – there we learned: One bathes the child [using hot water].16The presumption of this section is that one is not permitted to bathe on Shabbat with hot water, even if the water was heated before Shabbat.
The school of Rabbi Meir: One bathes the circumcision. Rabbi Yosei said: You17Whoever it is that teaches the halakha. should teach that one bathes the child.18And not one bathes the circumcision. Rabbi Ze’eira said: At all times, Rabbi Yosei would say to him: ‘Say over your mishna [one bathes the child], as we learned:19The following serves as a proof that the correct version of the Mishna is that one bathes "the child" and not only "the circumcision."
One does not withhold oil or hot water from upon a wound on Shabbat. Moreover, one may sprinkle hot water upon a wound on Shabbat. And if you say one bathes the circumcision, what is the difference between the wound of an adult and wound of a child. It is, rather, to teach you that one bathes the entire body of the child, which is not the case regarding an adult, as that [one] is only [allowed to bathe] the wound.’
Rabbi Elazar ben Azarya says: One bathes the child on the third day from circumcision that coincides with Shabbat. Rabbi Yaakov bar Aḥa said: At all times, Rabbi Yoḥanan and Rabbi Yonatan would instruct the midwives and say to them: ‘All the treatments that you administer during the week, perform them on Shabbat, on the third day that coincides with Shabbat.’ Shmuel said: It is due to danger. Rabbi Yosei said to him: ‘If it is due to danger, let us prepare hot water for him on Shabbat, as we learned: A person heats a cloth and places it upon his wound on Shabbat, and he may not take a bowl filled with hot water and place it on his belly on Shabbat,20This is for fear that the water will spill and cause a burn. but hot water for a cure is permitted.’
Rabbi Yehoshua ben Levi said: There is no prohibition; rather, it is permitted. 21Boiling water on Shabbat in order to bathe the child on the third day is permitted.