Eruvin, Chapter 10, Mishnah 14. This mishnah continues with a topic similar to the previous one, dealing with bandages and wounds that a kohen may have on Shabbos in the Beis HaMikdash.
"A Kohen Who Injured His Finger":
The mishnah opens: "Kohen shelakah be'etzba'o - korech alehah gemi bamikdash" - a kohen who was injured on his finger may wrap a reed around it in the Beis HaMikdash. The case is one where the finger is not in a place needed for the service, but it is simply not fitting for a wound to be open and exposed during the service, and therefore he wants to cover it. In the Mikdash he was permitted to wrap a gemi around it - a flexible reed - on Shabbos, even though a reed has a medicinal quality and a certain healing power. But "aval lakah bamedinah" - outside the Mikdash this is forbidden.
The Gemara draws attention to two conditions:
The location of the reed: The reed is not in a place where it forms a barrier between the kohen's hand and the vessel with which he performs the service - for example, the wound is on the left hand and the service is performed with the right.
A reed and not a garment: The mishnah specifically mentions a reed, which is a piece of plant material, and not a piece of cloth or a garment. For the moment the wrapping has the status of a garment, the problem of extra garments arises: a kohen may wear only four garments, precisely those four commanded in the Torah, and no more.
The mishnah continues regarding the use of the reed on the wound: "Lehotzi dam - kan vechan asur" - if his intention is to draw blood out of the wound, it is forbidden even in the Beis HaMikdash, since this serves no need of the service, and it constitutes a primary category of forbidden labor - a Torah prohibition on Shabbos.
Labors That Were Permitted in the Mikdash:
"Bozkin melach al gav hakevesh bishvil shelo yachliku" - it is permitted to crush salt and scatter it on the ramp leading up to the altar, so that the kohanim will not slip when the ramp becomes slippery. This is not considered building, adding to the ramp, or repairing on Shabbos, and therefore it is permitted. Outside the Mikdash, of course, this would not have been permitted.
"Umemal'in mibor hagolah umibor hagadol begalgal beShabbos" - they were permitted to draw water in the Beis HaMikdash by means of a pulley operated with a rope, and even though this is a mechanical device, it was permitted to use it on Shabbos at the two cisterns in the Mikdash - the Golah Cistern and the Great Cistern. This is so even though there is a concern that a person might use such a device to water his garden on Shabbos, and it is this concern that caused such a thing to be forbidden generally. But in the Mikdash they permitted it, so that the water could be drawn quickly.
The Cold Well: From this spring too, which was located outside the Beis HaMikdash, drawing was permitted. This was needed for the pilgrims who came up from the exile and arrived in Jerusalem on Yom Tov. The prophets who were among them, Zechariah and Malachi, permitted them to use a pulley and to draw from that spring on Yom Tov, because of the needs of the enormous numbers of people who came up to Jerusalem for the festival.
In summary: In this mishnah we learned the special leniencies stated for the Beis HaMikdash: wrapping a reed on a kohen's wound, provided that it does not form a barrier, is not a garment, and is not done to draw blood; scattering salt on the ramp so that the kohanim will not slip; and drawing water with a pulley from the Golah Cistern and the Great Cistern, as well as from the Cold Well by the permission of Zechariah and Malachi - all of these were permitted in the Mikdash and not outside it.