"Sacrifices") is the first tractate of Seder Kodashim ("Holy Things") of the Mishnah, the Talmud and the Tosefta.
This tractate discusses the topics related to the sacrificial system of the Temple in Jerusalem, namely the laws for animal and bird offerings, and the conditions which make them acceptable or not, as specified in the Torah, primarily in the book of Leviticus (Lev 1:2 and on).
The tractate has fourteen chapters divided into 101 mishnayot, or paragraphs.
(It was included in the siddur at this stage because it discusses all the sacrifices and the sages do not dispute within it.)
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