Shevuos, Chapter 6, Mishnah 5. This mishnah lists items on which no oath whatsoever is administered, and not only that, but additional halachos also do not apply to those very same items.
Which oaths are we talking about? All the types of oaths that have been explained: the oath of one who admits to part of a claim; an oath that a person is obligated in by Torah law when a single witness contradicts his words; and also the oath of watchmen, in which the Torah prescribed certain types of oaths, as will be explained. If a dispute arose between two people, for example over the question of who owns a certain slave, no oath is administered on it at all.
These are the items on which no oath is administered:
"Ha'avadim" - a dispute involving ownership of a slave.
"Vehashtaros" - a dispute concerning a document, that is, the question of who owns that document.
"Vehakeraos" - as we mentioned earlier, no oath is administered on real estate either.
"Vehahekdeshos" - anything belonging to hekdesh is also not subject to an oath.
The source of the law:
These laws are derived from the verses. The derashah teaches that in order for an oath to be required, the item must be movable, from which we learn that no oath is administered on real estate, and it must also have intrinsic value. Therefore:
A document: it has no intrinsic value. It represents value, but the document itself is not worth anything.
A slave: the Torah compares a slave to land, and therefore his status is like that of real estate.
Hekdesh: it is excluded for a different reason, since the section dealing with oaths uses the term "re'eihu" - when the matter concerns another person's money, and not when it concerns hekdesh.
Additional halachos that do not apply to these four items:
The mishnah continues and moves from the law of oaths to additional halachos, establishing that those very same items - slaves, documents, land and hekdesh - are excluded from them as well:
"Ein bahen tashlumei kefel" - one who steals any of them is not liable for the penalty of double payment, and this law too is derived from a derashah.
Fourfold and fivefold payment: one who steals an ox or a sheep and slaughters or sells it is liable for fourfold and fivefold payment, and this law does not apply when the animal belongs to hekdesh.
"Shomer chinam eino nishba" - an unpaid watchman is generally not liable when something happens to the item, but he is required to swear that he was not negligent and did not act carelessly. With these four items he is exempt even from this oath.
"Venosei sachar eino meshalem" - a paid watchman, who is generally obligated to pay if the item was stolen or lost, is exempt from payment when it comes to one of these four items.
The distinction regarding sacrifices:
Regarding sacrifices the mishnah adds an exception, and distinguishes between two categories:
"Kodashim shechayav be'achrayutan" - for example, an animal that a person designated to fulfill a vow he made to bring a korban. Regarding these, "nishba'in aleihen" - one does take an oath about them, since they have monetary value for him: if the animal was lost or stolen and is no longer in his possession, he is obligated to bring another animal in its place.
"V'she'eino chayav be'achrayutan" - when he said about a particular animal that this one is an olah or that this one is a shelamim, the responsibility does not rest upon him, and if it is lost he owes nothing. Therefore "ein nishba'in aleihen" - one does not take an oath about them, since their status is like the status of hekdesh mentioned earlier, about which one does not take an oath.
In summary: In this mishnah we learned that four things - slaves, documents, land and consecrated property - were excluded from the law of the oath, since the oath was stated regarding a movable object that has intrinsic value and regarding the money of "his fellow." We also learned that there is no double payment for them and no fourfold or fivefold payment, that an unpaid watchman does not take an oath about them, and that a paid watchman does not pay for them. Finally, we clarified the distinction within consecrated property: for consecrated property for which one bears responsibility, one does take an oath, whereas for consecrated property for which one does not bear responsibility, one does not take an oath.