Talmud - Pesahim 110b פסחים ק״י ב׳

your spices, which you use for your witchcraft, should scatter; the wind should carry away the fresh saffron that you witches hold to perform your witchcraft. As long as I was shown favor from Heaven and you showed me favor, I did not come here. Now that I have come here, your favor toward me has cooled and you should find favor.

The Gemara relates that in the West, Eretz Yisrael, they were not particular with regard to pairs. Rav Dimi from Neharde’a was particular about pairs even with regard to the signs on a barrel; he would not write pairs of symbols on a barrel. There was an incident in which there were pairs of symbols on a barrel and the barrel burst. The Gemara concludes: The rule of the matter is that all who are particular about pairs, the demons are particular with him; and if one is not particular, they are not particular with him. However, one is required to be concerned about the harm that might result from purposely performing actions in pairs.

When Rav Dimi came from Eretz Yisrael to Babylonia, he said: With regard to two eggs, two nuts, two cucumbers, and another matter, there is a halakha transmitted to Moses from Sinai that they are dangerous in pairs. But the Sages are uncertain about what the other matter is, and therefore the Sages decreed that all pairs are prohibited due to that other matter.

And the Gemara notes that that which we said above, that the numbers ten, eight, six, and four do not cause the danger associated with pairs, we said only with regard to harmful spirits. However, with regard to witchcraft, we are concerned even with regard to one who performed an activity a greater number of times.

This is like that incident involving a certain man who divorced his wife. She went and married a shopkeeper who sold wine in his store. Every day, the first husband would go and drink wine in that shop. His ex-wife would perform witchcraft upon him, and it would not be effective for her in her attempts to harm him because he was careful with regard to pairs.

One day he drank a lot, and he did not know how much he drank. Until he drank sixteen cups, he was lucid and was careful with regard to himself, to keep track of how many cups he had drunk. From here onward he was not lucid and was not careful to watch himself, and she caused him to leave after having consumed a pair, i.e., an even number of cups. As he walked, a certain Arab met him and, noticing that he was bewitched, said to him: It is a dead man who walks here. He went and hugged a palm tree for support; the palm tree dried out due to the witchcraft, and he burst.

Rav Avira said: Plates and loaves do not contain the element of danger associated with pairs. The Gemara elaborates upon this point: The rule of the matter is that anything whose production was completed by people, whether a vessel or food, they do not contain the element of danger associated with pairs. Conversely, if the object was completed by Heaven, e.g., with regard to types of food, we are concerned.

Furthermore, a store does not contain the element of danger associated with pairs. If one eats there, there is no danger, as this is not his regular place. If one changed one’s mind after drinking an odd number of cups and added one more, his drinking does not contain the element of danger associated with pairs, as he did not initially intend to drink an even number. The behavior of a guest who eats or drinks in someone else’s house does not contain the element of danger associated with pairs, as his host determines how much he will eat and drink. The behavior of a woman does not contain the element of danger associated with pairs, as demons are not particular with regard to how much a woman eats or drinks. But if she is an important woman, we are concerned.

Rav Ḥinnana, son of Rav Yehoshua, said: Isparegus, a wine-based drink with added spices that people would regularly consume in the morning, combines with the number of cups of wine one has already consumed for the good, to raise the total to an odd number, and does not combine for the bad, to bring the sum to an even number.

Ravina said in the name of Rava: If one is in doubt as to whether he has drunk in pairs, he should be stringent and drink another cup. And some say that one who is uncertain with regard to pairs should be lenient and not drink an additional cup, lest the additional cup be the even number. Rav Yosef said: Two cups of wine and one cup of beer do not combine; two cups of beer and one cup of wine do combine.

And this is your mnemonic by which to remember this rule is a mishna concerning the halakhot of ritual purity. This is the rule: With regard to anything attached to an object, if the smaller piece is more stringent than the larger one, the combined object is ritually impure; if the attached substance is more lenient than it, the combined object is ritually pure. In other words, if a small piece of a type of fabric that contracts ritual impurity when it is relatively small, which is a stringency, is attached to a larger object comprised of a less valuable fabric that contracts ritual impurity only when it is bigger, the two materials combine to form a unified fabric that contracts ritual impurity if together they amount to the larger requisite size. However, if there is more of the stringent material, the two substances do not combine halakhically to form the amount of the smaller requisite size. Similarly, in the case of pairs, the wine is more significant than the beer. Therefore, the wine combines with the beer but not vice versa.

Rav Naḥman said that Rav said: If one drinks two cups before the table is brought and the meal begins and one cup over the table they combine, the person is not considered to have drunk a pair of cups. However, if one drinks one cup before the table is brought and two cups over the table they do not combine; the two cups he drank during the meal are considered a pair.

Rav Mesharshiya strongly objects to this ruling: Is that to say that we need to resolve the problem of pairs with regard to the table? Is the presence of the table the decisive factor here? We need to resolve the problem with regard to the person, and with regard to the person it is considered resolved. He began drinking before the table was brought, and he has consumed an odd number of cups.

Rather, Rav Mesharshiya said: Everyone agrees that if one drank two cups over the table during the meal and one after the table has been removed, they do not combine. This is like that incident involving Rabba bar Naḥmani, in which someone drank in pairs and was harmed. Rabba instructed them to return the table so that the man could drink an additional cup over the table. This shows that the additional cup counts only if the drinker returns to the table.

Rav Yehuda said that Shmuel said: Any type of drink that is diluted combines to form an even or odd number,

Traduction : The William Davidson digital edition of the Koren Noé Talmud, with commentary by Rabbi Adin Even-Israel Steinsaltz.

Pesachim 110b explores the danger of pairs in Jewish folklore, discussing demons, witchcraft rituals, and superstitions surrounding repeated actions.