Kezayit, k'zayit, or kezayis () is a

Talmud The Talmud (; he, , Talmūḏ) is the central text of Rabbinic Judaism and the primary source of Jewish religious law (''halakha'') and Jewish theology. Until the advent of modernity, in nearly all Jewish communities, the Talmud was the cente ...

unit of volume A unit of volume is a unit of measurement for measuring volume or capacity, the extent of an object or space in three dimensions. Units of capacity may be used to specify the volume of fluids or bulk goods, for example water, rice, sugar, grain or ...

approximately equal to the size of an average

olive The olive, botanical name ''Olea europaea'', meaning 'European olive' in Latin, is a species of small tree or shrub in the family Oleaceae, found traditionally in the Mediterranean Basin. When in shrub form, it is known as ''Olea europaea'' ...

. The word itself literally means "like an olive." The rabbis differ on the precise definition of the unit: * Rabbeinu Yitzchak (the Ri) defines it as one-half of a beytza (a beytza is the volume of an egg). *

Maimonides Musa ibn Maimon (1138–1204), commonly known as Maimonides (); la, Moses Maimonides and also referred to by the acronym Rambam ( he, רמב״ם), was a Sephardic Jewish philosopher who became one of the most prolific and influential Torah ...

specified that a 'grogeret' (dried fig) was one-third of a beytza, making this the maximum size for a kezayit, which is smaller. Rabbeinu Tam made the argument explicitly, though, using a slightly different calculation came out with a maximum definition of three-tenths. * According to some interpretations, including the

Chazon Ish Avraham Yeshaya Karelitz (7 November 1878 – 24 October 1953), also known as the Chazon Ish () after his magnum opus, was a Belarusian-born Orthodox rabbi who later became one of the leaders of Haredi Judaism in Israel, where he spent his f ...

, the ''zayit'' is not related to other units by a fixed ratio, but rather should only be conceived of independently as the size of an average olive. Its uses in

halacha ''Halakha'' (; he, הֲלָכָה, ), also transliterated as ''halacha'', ''halakhah'', and ''halocho'' ( ), is the collective body of Jewish religious laws which is derived from the written and Oral Torah. Halakha is based on biblical commandm ...

include: * The minimum amount food that, when eaten, is halachically considered "eating." This has implications throughout the spectrum of halacha, including: ** For prohibitions of consumption, as in the eating of ''

milk and meat Mixtures of milk and meat ( he, בשר בחלב, basar bechalav, meat in milk) are forbidden according to Jewish law. This dietary law, basic to kashrut, is based on two verses in the Book of Exodus, which forbid "boiling a (goat) kid in its m ...

'' ** For the saying of a

Bracha Ahrona Birkat Hamazon ( he, בִּרְכַּת הַמָּזוׂן, The Blessing of the Food), known in English as the Grace After Meals ( yi, ; translit. ''bentschen'' or "to bless", Yinglish: Bentsching), is a set of Hebrew blessings that Jewish ...

(the traditional grace after meals) * People exposed to at least a ''kezayit'' of the flesh of a dead body become

ritually impure Ritual purification is the ritual prescribed by a religion by which a person is considered to be free of ''uncleanliness'', especially prior to the worship of a deity, and ritual purity is a state of ritual cleanliness. Ritual purification may ...

See also