Shabbos Daf 134 שבת דַף 134

The Gemara brings a Baraisa that states, דברים שאין עושין למילה בשבת עושין לה ביום טוב – Things that we may not do for a milah on Shabbos, we may do on Yom Tov, such as crushing cumin, and vigorously mixing together oil and wine. The Mishnah earlier forbid these two actions to be done on Shabbos.

Abaye  asked Rav Yosef that just as it is muttar to crush cumin on Yom Tov because it is permitted to do melacha on Yom Tov if it is for the purpose of eating, so too it should be permitted to vigorously mix oil and wine on Shabbos because it is fit to be used for a sick person? (Rashi explains that the Gemara is referring to a חולה שאין בו סכנה – a sick person who is not in danger, since any melacha can be done for a חולה שיש בו סכנה - a sick person who is dangerously ill.)

Rav Yosef answers that the Baraisa is dealing with preparing medication for sick people, which does not require a vigorous mixing. Our Mishnah is addressing preparing medication for a milah, which does require a vigorous mixing, and therefore it is forbidden to do on Shabbos.

Abaye shares many pieces of advice that his adopted mother gave him regarding treating infants with various ailments. The final piece of advice was that if an infant whose body has a reddish hue, it is because his blood is not absorbed into his flesh. Rashi explains that his blood is located between the skin and the flesh, and the child might bleed to death from the circumcision. Therefore, one should wait to perform the circumcision until his blood is absorbed in his flesh.

Similarly, if an infant’s body has a yellow  hue, it is due to the infant being blood deficient. Rashi  explains that this condition leaves him very weak with the risk of death from a circumcision. Therefore, one should wait until the infant is full blooded and then circumcise him.

The next Mishnah introduces a machlokes regarding bathing an infant before and after milah.