What is the minimum measure for the impurity of foods? For them to contract impurity, even the slightest amount. Even a sesame or mustard seed contracts impurity, as Leviticus 11:34 states: "Any food that shall be eaten," including even the slightest amount. Food does not impart impurity to other foods or liquids or a person's hands until it is the size of an egg without its shell. And a person who partakes of impure foods is not disqualified from partaking of terumah and sacrificial foods unless he partakes of a portion of impure food the size of an egg and a half. This is half a p'ras.
Even the slightest amount of liquid can contract ritual impurity and impart ritual impurity. Even a drop of an impure liquid the size of a mustard seed that touched foods, keilim, or other liquids causes them to become impure. Nevertheless, a person who drinks impure liquids does not become disqualified unless he drinks a revi'it, as we explained.
All liquids can be combined to comprise the minimum measure and disqualify a person's body if he drank a revi'it. All foods can be combined to comprise the minimum measure of an egg-sized portion that imparts the impurity associated with foods and to a half a pras to disqualify a person. Even wheat can be combined with flour, with dough, with figs, with meat and the like. Everything can be combined.
⚖️ Minimum Measures
Food contracts impurity in any amount, even a sesame seed, but only imparts impurity when an egg-sized portion is present. Liquids contract and impart impurity in even the smallest drop. All liquids combine toward the measure that disqualifies a person, and all foods combine toward the egg-size required to impart impurity.
4/7
Measuring Food: Attachment, Shrinkage, and Swelling
When an animal's hide is connected to its meat, the juice it secretes, the spices, the meat connected to the hide - although one had the intent to eat part of it and did not have the intent to eat the remainder, even though part of it was separated by a beast of prey and part of it was separated by a knife - the bones that are connected to the meat, the giddim, the soft portions of the horns and the hoofs, the thin feathers and the wooly hairs of a fowl, the soft portion of its nails and the beak that are embedded in its flesh: all of these contract impurity, impart impurity, and are included in an egg-sized portion or half a pras.
When an egg-sized portion of impure food was left in the sun and it shrank, it does not impart impurity. Similarly, an olive-sized portion from a human corpse or an animal carcass and a lentil-sized portion from a dead creeping animal that was left in the sun and shrank are pure.
When an olive-sized portion of fat, blood, notar, or piggul was left in the sun and it shrank, one is not liable for karet for partaking of them. If he left them in the rain and they swelled, returning to the specified volume, they return to their original status, whether that involves severe impurity, a lesser impurity, or a prohibition against partaking of the substance.
Onion leaves and onion shoots that are hollow which possess sap are measured according to their present size. If they are hollow and empty, their hollow should be compressed before their volume is measured.
When the meat of a calf expands or the meat of an older animal shrinks, its volume should be measured in its present state.
📏 How to Measure
An animal's hide connected to meat is measured together with the food. Food that shrinks in the sun loses its ability to impart impurity; if it swells in rain back to volume, the question is unresolved. Hollow bread or vegetables are compressed before measuring. Meat is measured in its present state regardless of expansion or shrinkage.
5/7
Combining Foods of Similar and Dissimilar Impurity
All entities whose type of impurity and minimum measures are similar can be combined with each other to reach that measure. If their impurity was similar, but not the minimum measures or the minimum measures, but not the impurity, they should not be combined, not even to impart the lesser type of impurity. What is meant by the type of its impurity, but not the minimum measure? E.g., the flesh of a corpse and the decomposed mass from it. What is meant by its minimum measure, but not its type? E.g., the flesh of a human corpse and the flesh of an animal carcass. Needless to say, impure entities that are not similar, neither in their measure and their type of impurity, e.g., the flesh of an animal carcass and the flesh of a dead crawling animal, are not combined.
The measure of all impure food is the same. For all impure foods do not impart impurity unless there is an egg-sized portion present. And their impurity is of the same type, for all impure foods impart impurity only through touch and they do not impart impurity to humans or to keilim. Therefore, they can be combined to impart impurity according to the lesser level of impurity among them. What is implied? When there was a half an egg-sized portion of food that was a primary derivative of impurity and a half of an egg-sized portion of food that was a secondary derivative that were mixed together, they are considered as an egg-sized portion that is a secondary derivative. If the mixture touches food that was terumah, it disqualifies it. When there was a half an egg-sized portion of food that was a secondary derivative of impurity and a half of an egg-sized portion of food that was a tertiary derivative that were mixed together, they are considered as an egg-sized portion that is a tertiary derivative. Similar laws apply in all analogous situations. Even when there was a half an egg-sized portion of food that was a primary derivative and a half of an egg-sized portion of sacrificial food that was a fourth degree derivative that were mixed together, they are considered as an egg-sized portion that is a fourth degree derivative.
When an egg-sized portion of food that was a primary derivative of impurity and an egg-sized portion of food that was a secondary derivative were mixed together, the entire mixture is considered as a primary derivative. If the mixture was divided, each portion is a secondary derivative. If one of the portions of the mixture that was divided fell on a loaf of bread that was terumah and then the other fell upon it, they disqualify it. If the two fell at the same time, they cause it to be considered as a secondary derivative.
When an egg-sized portion of food that was a secondary derivative of impurity and an egg-sized portion of food that was a tertiary derivative were mixed together, the entire mixture is considered as a secondary derivative. If the mixture was divided, each portion is a tertiary derivative. If one of the portions of the mixture that was divided fell on a loaf of bread that was terumah and then the other fell upon it, they do not disqualify it. If the two fell at the same time, they cause it to be considered as a tertiary derivative.
When an egg-sized portion of food that was a primary derivative of impurity and an egg-sized portion of food that was a tertiary derivative were mixed together, the entire mixture is considered as a primary derivative. If the mixture was divided, each portion is a secondary derivative. The rationale is that when a tertiary derivative touches a primary derivative, it becomes a secondary derivative.
When two egg-sized portions of food that were primary derivatives of impurity and two egg-sized portions of food that were secondary derivatives were mixed together, the entire mixture is considered as a primary derivative. If the mixture was divided in half, each portion is a primary derivative. If they were divided into three or four portions, each one of them is considered a secondary derivative. Similarly, when two egg-sized portions of food that were secondary derivatives of impurity and two egg-sized portions of food that were tertiary derivatives were mixed together, the entire mixture is considered as a secondary derivative. If the mixture was divided in half, each portion is a secondary derivative. If they were divided into three or four portions, each one of them is considered a tertiary derivative.
🔗 Combining Impurities
Foods can only be combined to reach the minimum measure if their type and degree of impurity are identical. When primary and secondary derivatives are mixed, the more severe grade governs the entire mixture. Upon division, each portion retains the original degree of impurity it had before mixing. Two egg-sized primary portions mixed with two secondary portions yield a primary mixture.
6/7
🎓 Key Principles
Chapter 4
🌱
Any Amount Can Contract; Egg-Size Required to Impart Food becomes impure in any quantity but can only make other things impure once it reaches an egg-sized volume.
💧
Liquids: No Minimum for Contraction or Transmission Even a single drop of impure liquid can contract impurity and transmit it to foods, vessels, or other liquids.
☀️
Sun Shrinkage Nullifies Impurity Transmission Food that shrinks below the required measure in the sun can no longer impart impurity to other items.
📊
Severity Governs Mixtures When different grades of impure food are mixed together, the most severe grade determines the status of the entire mixture.