Shabbos, Mishnah 2. We continue with the laws of milah. The Mishnah opens: "Osin kol tzorchei milah b'Shabbos" - we perform all the needs of the milah on Shabbos - and it details which things may be done on Shabbos for the sake of the milah. As we learned in the previous Mishnah, according to Rabbi Akiva only those labors that could not have been done before Shabbos are permitted.
These are the needs of the milah that are performed on Shabbos:
Cutting the foreskin - the milah itself.
Periah - drawing back the inner membrane that covers the organ.
Metzitzah - drawing out the blood.
Applying remedies to the site of the milah:
One may place on the wound a compress, which is a healing bandage, and also cumin, which was customarily applied for medicinal purposes. The cumin, however, must be prepared and ground before Shabbos. And what is the law if the cumin was not ground before Shabbos? One may chew it with his teeth and place it on the wound, that is, do it in an unusual manner.
The same applies to wine and oil, which also serve as remedies: if he did not beat and mix them before Shabbos - even though he could have done so - he may not mix them on Shabbos. But he may put each one separately into the dish, and if they mixed together on their own, this is permitted, and that is a sufficient change from the usual manner.
The wrap and the bandage:
It was customary to make a kind of small sleeve that was placed over the site of the milah, in order to keep the skin that was drawn back from returning and covering the organ. This sleeve may not be made on Shabbos, and it must be prepared before Shabbos. But one may wrap a cloth or a rag around the wound.
Bringing the rag on Shabbos:
If he did not prepare a rag before Shabbos and did not bring it to his home, he may wrap it around his finger and bring it that way, and even from another courtyard with which he has no eruv. Through a public domain it is forbidden to bring it, but from courtyard to courtyard it is permitted.
The reason is this: the prohibition of carrying from courtyard to courtyard without an eruv is only rabbinic, and therefore they permitted bringing it by way of wearing it. This is not full-fledged wearing - for if the rag were considered an actual garment, it would be permitted to go out with it even into a public domain. Rather, it is only partial wearing, and that is enough to permit it where the prohibition is rabbinic, but not in a public domain.