Treatise in the Mishnah, Tosefta, and Babylonian Talmud mainly concerned with the regulations in Lev. xxvii. 10, 33 regarding the exchange of consecrated things. In most editions of the Mishnah this treatise is the sixth in the order Ḳodashim. It is divided into seven chapters, containing altogether thirty-four paragraphs.
- Ch. i.: Regarding those who are allowed to make an exchange; things that may be exchanged, and things that may not be exchanged (§§ 3-6). Regulations concerning drawn water which is unfit for the miḳweh; concerning water for sprinkling, and a field in which there is a grave that can not be found (§§ 4-5).
- Ch. ii.: In what ways the sacrifices of the congregation are different from the sacrifices of individuals (§§ 1-2). Difficulties connected with consecrated objects in general which do not affect objects consecrated through temurah and vice versa (§ 3).
- Ch. iii.: Sacrifices in which the young of the sacrificial animal is equivalent to the sacrificial animal itself; sacrifices in which this is not the case (§§ 1-2). What must be done when some one consecrates a female animal for a sacrifice for which only a male animal is appropriate (§§ 3-4). In what ways the first-born and the tenth are different from other sacrificial animals (§ 5).
- Ch. iv.: The young of a sin-offering; temurah in connection with a sin-offering; other regulations concerning sin-offerings. Cases in which the bringer of the sin-offering dies before the sacrifice is made; in which the sin-offering has been lost and found again; in which a sin-offering with a blemish is consecrated.
- Ch. v.: How, an animal being pregnant, its young may be consecrated while still unborn (§§ 1-3). The form of words with which a temurah is made.
- Ch. vi.: Things that may not be placed on the altar (§§ 1-4). The young of animals which may not be placed on the altar may be sacrificed; sacrificial animals which have become unfit ("ṭerefah") through sickness may not be redeemed (§ 5).
- Ch. vii.: In what ways things which have been consecrated for the altar are different from things which are dedicated only for the maintenance of the Temple, and in what ways they are similar (§§ 1-3). What sacrificial objects must be burned and what buried; in this connection are enumerated other unconsecrated things which must be partly burned and partly buried (§§ 4-6).
The Tosefta to this treatise is divided into four chapters, and contains various additions to and amplifications of the Mishnah. The Gemara of the Babylonian Talmud contains, in addition to the discussions and explanations of the Mishnah, many interesting haggadic utterances. Of these, two deserve special notice: (1) the saying concerning the custom of not writing down sentences of oral teaching, and how this was abrogated because if it had been adhered to the oral teaching would have been forgotten (14b), and (2) that concerning the numerous halakic utterances which were forgotten in the days of mourning for the death of Moses (16a).