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

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

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 dimension (mathematics), dimensions. Units of capacity may be used to specify the volume of fluids or bulk goods, for example wat ...

approximately equal to the size of an average Talmudic-Era Israeli

olive The olive, botanical name ''Olea europaea'' ("European olive"), is a species of Subtropics, subtropical evergreen tree in the Family (biology), family Oleaceae. Originating in Anatolia, Asia Minor, it is abundant throughout the Mediterranean ...

. 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 (the volume of a Talmudic-Era chicken egg, literally meaning “egg”). *

Maimonides Moses ben Maimon (1138–1204), commonly known as Maimonides (, ) and also referred to by the Hebrew acronym Rambam (), was a Sephardic rabbi and Jewish philosophy, philosopher who became one of the most prolific and influential Torah schola ...

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 Yeshayahu 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 ...

, 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'' ( ; , ), also transliterated as ''halacha'', ''halakhah'', and ''halocho'' ( ), is the collective body of Jewish religious laws that are derived from the Written and Oral Torah. ''Halakha'' is based on biblical commandments ('' mi ...

include: * The minimum amount of 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 The mixture of meat and dairy () is 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 mother's milk" and a third repetition of this pro ...

'' ** For the saying of a

Bracha Ahrona Birkat Hamazon ( "The Blessing of the Food"), known in English as the Grace After Meals ( "to bless", Yinglish: Bentsching), is a set of Hebrew blessings that Jewish law prescribes following a meal that includes at least a kezayit (olive-sized ...

(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 a ritual prescribed by a religion through which a person is considered to be freed of ''uncleanliness'', especially prior to the worship of a deity, and ritual purity is a state of ritual cleanliness. Ritual purification ...

References

{{Judaism-stub

See also

References