poison

Distinctions

Eres (ארס)

Not in Tanach or Mishnah; it appears in Hebrew passages of the Bavli and a handful of times in the Yerushalmi, there almost always with a yud after the aleph, so likely iras. The Gemara's usage fixes the sense. Avodah Zarah 30b: three kinds of eres, a young snake's which sinks in a liquid, an old snake's which flows on top, a middle-aged one's which dallies in between (Sukkah 50a, Bava Kamma 115b). Avodah Zarah 31b: all sheratzim have eres, but only a snake's is lethal. Sanhedrin 78a and Bava Kamma 23b ask whether a snake releases venom only when angered or whether the venom sits always on its teeth. So eres is specifically venom, most often a snake's; this is what Bigsan and Seresh meant to put in Achashverosh's cup (Megillah 13b). An alternate tradition has them planning to kill him in his sleep and present his severed head to the Greek kings (Yossiphon ch. 4), and Targum Rishon to Esther 2:21 combines the two, having them poison Esther with a sam hamaves first and then slay her husband; Targum Sheini there has them put a poisonous snake in the king's golden cup instead.

The origins of eres are shrouded in mystery.

• Eminent etymologists derive it from the Latin virus: Dr. Alexander Kohut (1842-1894), Rabbi Ernest Klein (1899-1983) and Avraham Even-Shoshan (1906-1984).
• The Comprehensive Aramaic Lexicon calls that derivation "highly dubious," so the question stands open.

Sam hamaves (סם המות)

Literally the potion of death. Not in Tanach; once in Mishnah, where an animal that swallowed sam hamaves or was bitten by a snake is no tereifah but is still forbidden as dangerous (Chullin 3:5). The two are listed separately there, which shows sam hamaves is not venom. In the Gemara: whether a radish is sam hachaim or sam hamaves (Eruvin 56a), Torah learned without proper intent (Taanis 7a), a mother's oath on her child's life (Gittin 35a), and liability for killing another's animal by feeding it (Bava Kamma 47b, 56a).

• Because sin and samech are often understood to interchange, Midrash Sechel Tov, Midrash Aggadah and Daas Zekeinim read vayusam lefanav le'echol (Bereishis 24:33) as a hint that Besuel tried to poison Eliezer; a commentary ascribed to Rashi on Divrei HaYamim II 22:10 has Asaliah killing this way too.
• Rabbi Shlomo Pappenheim of Breslau (1740-1814) takes ס-ם / ש-ם as putting a thing in its place, and derives samim, the ketores ingredients (Shemos 30:7, 30:34, 40:27; Vayikra 16:12; Divrei HaYamim II 2:3, 13:11), from their being stowed in specially designated places.

It seems from all this, Rabbi Reuven Chaim Klein concludes, that sam hamaves is the general word, covering any lethal preparation and naming none in particular.

Targum Yonasan renders nashchisah etz belachmo (Yirmiyahu 11:19) as nirmei sama demosa bemeichleih, let us cast deadly poison into his food.

Rosh (ראש / רוש), chamat (חמת)

Rosh: Devarim 29:17, Iyov 20:16, Eichah 3:19 and elsewhere.

• Targum and Rashi (to Yirmiyahu 8:14) take it as poison drawn from a snake's rosh, its head, so essentially venom. It is normally spelled with an aleph, like the word for head, once with a vav (Devarim 32:32).
• Other sources take it as a poisonous plant extract, Rabbi Dr. Yehuda Feliks (1921-2004) writing that rosh is best identified with poppy and opium or with conium, and to that effect Pappenheim traces it to ר-ש, head, for that plant's round top, which resembles a head.
• Rav Hirsch (to Devarim 29:17) clarifies that this deadly extract can come from both the plant kingdom and the animal kingdom.

Chamat (Devarim 32:33, Tehillim 58:5) is poison named for what a snake emits when its cheimah is aroused.

Ra'al (רעל) and tarelah (תרעלה)

Nachum 2:4, Zecharyah 12:2; tarelah in Tehillim 60:5, Yeshayahu 51:17, 51:22.

• Commonly rendered poison, but Rashi (to Yeshayahu 51:17 and Nachum 2:4) says it is a concoction that leaves a man weak and immobile, as though tied up and detained. A near word re'alah (Yeshayahu 3:19) is an ornament one wraps oneself in.
• Radak (to Yeshayahu 51:17 and in Sefer HaShorashim) cites the poison reading but also defines the word as shake, rattle and roll, akin to ro'ed, to which it might be etymologically connected through the interchangeability of lamed and dalet.

Rabbi Reuven Chaim Klein offers his own hedged reconciliation of the two readings: perhaps ra'al names a toxic contagion that throws a man into seizure-like convulsions, rather than a lethal poison. In Modern Hebrew ra'al is deadly poison.

Eches (עכס)

A separate dispute, since Rashi reads it as venom. Yeshayahu 3:16 has uvragleihem te'akasnah as a verb, and one that appears nowhere else in Tanach, so what it denotes is unclear; 3:18 has ha'achasim as an ornament, which Rashi and Ibn Ezra (to 3:18) explain as special shoes.

• The Gemara (Shabbos 62b, Yoma 9b): the Bnos Tzion put perfumes in their shoes and, meeting the young men in Yerushalayim's markets, kicked their feet to spray the fragrance at them shamefully, infecting them with the yetzer hara, which works like eres. On that basis Rashi (to Yeshayahu 3:16) glosses eches as snake venom and the verb as poisoning them to sin; the Vilna Gaon joins the two senses by taking eches as shoes enclosed in snakeskin.
• Ibn Ezra and Radak (to 3:16) dissent, tying the verb to the noun: the women drew attention to themselves by the noise of their shoes, which Radak adds chimed like bells in a steady beat. Rabbi Reuven Chaim Klein adds a suggestion of his own, which these commentators do not make: perhaps that sense too runs back to snakes, since the sound resembles a rattlesnake's rattle.
• At Mishlei 7:22 Rashi again reads venom, while Rabbi Yeshayah of Trani (1180-1250) takes it as a prisoner's ball and chain, which ties back to the shoe sense since both are fastened to the feet (so too Ibn Ezra there and Radak in Sefer HaShorashim); the point of the analogy, Rabbi Klein suggests, is presumably that a sin is bound to a man forever and resurfaces on the Day of Judgment (Sotah 3b).

Others explain eches as "dog."

• Dr. Alexander Kohut was the first to note that Rashi's reading of eches as snake venom was likely informed by the Greek echis, viper, and echis does seem to appear in rabbinic literature in that sense, since the Midrash renders efeh, a Biblical snake, as echis (Midrash Tanchuma, Beshalach 18, and Mechilta to Shemos 15:22).
• Rashi himself (to Shabbos 62b) gives a different etymology of eches: a metathesis of ka'as, anger, since a snake emits venom only when angered.
• Rabbeinu Efrayim supposes the converse, that ka'as is a metathesis of eches, since anger puts a sort of poison in a man's heart.

Either way, the connection is already in the Gemara, which expounds the name of Kalev's daughter Achsah (Yehoshua 15:16-17, Shoftim 1:12-13, Divrei HaYamim I 2:49) as one at whom every man who saw her grew angry (ka'as) at his wife, which Rashi explains to mean that she was so beautiful that the comparison might make a man angry at his wife for falling short; the exegesis rests on the metathesis of ע-כ-ס against כ-ע-ס. The great Italian mekubal Rabbi Menachem Azariah of Fano (1548-1620) reads her name as marking her a gilgul of Tzipporah, who saved Moshe from death by nachash through circumcising their child (Shemos 4:24-26).

La'anah (לענה)

Rabbi Shlomo of Urbino (Ohel Moed) counts la'anah a synonym of rosh, chamat and ra'al, all poison. This is quite novel: the earlier commentators, such as Rashi and Radak, call la'anah very bitter but do not write that it is deadly.

Sources

Rabbi Reuven Chaim Klein, "Pick Your Poison," What's in a Word?, Ohr Somayach, 5 March 2022.

Rabbi Reuven Chaim Klein, "Bereishis: In the Beginning...," What's in a Word?, Ohr Somayach, 26 October 2024.

Rabbi Reuven Chaim Klein, "Pick your Poison," What's in a Word? Synonyms in the Hebrew Language (book manuscript).

Cited in the essay: Bereishis 24:33 with Midrash Sechel Tov, Midrash Aggadah and Daas Zekeinim; Shemos 4:24-26, 15:22, 30:7, 30:34, 40:27; Vayikra 16:12; Devarim 29:17, 32:32, 32:33; Yehoshua 15:16-17; Shoftim 1:12-13; Yeshayahu 3:16, 3:18, 3:19, 51:17, 51:22; Yirmiyahu 8:14; Nachum 2:4; Zecharyah 12:2; Tehillim 58:5, 60:5; Mishlei 7:22; Iyov 20:16; Eichah 3:19; Divrei HaYamim I 2:49, II 2:3, 13:11, 22:10; Esther 2:21 with Targum Rishon and Targum Sheini; Yossiphon ch. 4; Megillah 13b; Shabbos 62b; Yoma 9b; Eruvin 56a; Taanis 7a; Gittin 35a; Sotah 3b; Avodah Zarah 30b, 31b; Sukkah 50a; Sanhedrin 78a; Bava Kamma 23b, 47b, 56a, 115b; Mishnah Chullin 3:5; Mechilta to Shemos 15:22; Midrash Tanchuma, Beshalach 18; Targum; Rashi, Ibn Ezra and Radak (with Sefer HaShorashim) to the pesukim above; the Vilna Gaon; Rabbi Yeshayah of Trani; Rabbeinu Efrayim; Rabbi Menachem Azariah of Fano; Rabbi Shlomo Pappenheim; Rabbi Shlomo of Urbino, Ohel Moed; Rabbi Dr. Yehuda Feliks; Dr. Alexander Kohut; Rabbi Ernest Klein; Avraham Even-Shoshan; the Comprehensive Aramaic Lexicon; Rav Hirsch to Devarim 29:17; Targum Yonasan to Yirmiyahu 11:19.