Maaser Sheni, Chapter 3, Mishnah 8. The previous Mishnah dealt with the boundary of Jerusalem - what counts as part of Jerusalem and what does not, with regard to Maaser Sheni. Now we step aside from Maaser Sheni, but remain with a similar concept, and turn to discuss the Temple itself: the chambers - the offices and rooms that were in use in the Temple - and the question of when they have the status of holy ground and when they have the status of ordinary ground.
"shehen benuyos bakodesh ufesuchos lachol":
The body of the room itself is built in the holy area, that is, within the bounds of the Azarah - the Temple courtyard - but its entrance faces the ordinary area, the region outside the Azarah. The halachah in such chambers is "tochan chol vegagoseihen kodesh":
Tochan chol: The interior of the chamber has the status of ordinary ground, it does not have the status of the Azarah, and one may not eat the most holy offerings there.
Vegagoseihen kodesh: The roof of those chambers is considered holy, and has the status of the Azarah.
The Gemara clarifies that this refers specifically to rooms whose roofs are at the same height as the floor of the Azarah. If they are not at the same height, they do not have the status of holy ground, since the rule is that the roofs and upper stories in the Temple were not sanctified.
"benuyos bakodesh uvachol ufesuchos lakodesh velachol":
Here the Mishnah speaks of chambers built in both areas at once - they cover an area of holy ground and an area of ordinary ground - and their entrances face both the holy area and the ordinary area. About this the Mishnah says: "tochan vegagoseihen, mikeneged hakodesh velakodesh - kodesh, mikeneged hachol velachol - chol". That is, both the interior and the roofs (roofs that are at the height of the Azarah floor) are divided according to the dividing line:
Mikeneged hakodesh velakodesh: The part that lies opposite the holy wall of the Azarah and inward - its status is holy.
Mikeneged hachol velachol: Any part that lies opposite the dividing line outside the wall of the Azarah - its status is ordinary.
It emerges that the room itself is divided within: at the point where the dividing line passes, that part of the room is treated as holy, and the other part is treated as ordinary.
In summary: In this Mishnah we learned the law of the chambers in the Temple. A chamber built in the holy area and opening to the ordinary area - its interior is ordinary and its roof is holy, provided that its roof is at the height of the Azarah floor, since the roofs and upper stories in the Temple were not sanctified. And a chamber built both in the holy area and in the ordinary area, opening both to the holy area and to the ordinary area - its interior and its roof are divided according to the dividing line: what lies opposite the holy area and inward is holy, and what lies opposite the ordinary area and outward is ordinary.