nature
tigris
At a glance
In short
Chidekel and Diglat are one river under two names, the Tigris: Chidekel is the Biblical name, Diglat the later one that Targum and Shas use. Rashi states explicitly that the Diglat of the Gemara is the Chidekel of Tanach, and Shadal observes that the two names are cognates, Chidekel Hebrew and Diglat Aramaic. Berachos 59b expounds Chidekel as chad (sharp) and kal (light, swift). Tigras in Chullin 59b is a separate word for an animal, not the river, though Abarbanel and Rabbi Binyamin Mussafia tie the river's name Tigris to the tiger.
Distinctions
Chidekel (חדקל)
The borders of Eretz Yisrael reach the Euphrates in Devarim 1:7 and in Shemos 23:31 as Targum Onkelos and Rashi read it, against the Yarden of Bamidbar 34:12; Mesopotamia, the Greek "land between two rivers," lies between the Euphrates and the Tigris. Chidekel appears twice in Tanach: Bereishis 2:14, the third of the four rivers of Eden, east of Ashur; and Daniel 10:4, "the Great River that is Chidekel," vocalized Chidakel there because a segolite word at the end of a pasuk turns its segol to kamatz. Berachos 59b expounds it as chad, sharp, and kal, light or swift. The same exegesis appears in Josephus (Antiquities 1.1.3), for whom the name signifies "swift, with narrowness," and in Bereishis Rabbah 16:4, where the four rivers allude to the four kingdoms and Chidekel to Greece, whose decrees were sharp and swift. (Jewish philosophers such as Rabbi Levi ben Avraham and Rabbi Nissim of Marseilles connect the four rivers to the four elements, Chidekel alluding to water.)
Diglat (דגלת)
Targum Onkelos renders Chidekel as Diglat, and Targum uses it again at Nachum 1:12 where the Hebrew has no river-name. Wherever the Gemara refers to the river it is the Diglat: Rava threw glass shards and thorns into it (Bava Kamma 30a); at his prayer for rain the gutters of Mechoza flooded down to it (Taanis 24b); other mentions come with Rava (Eruvin 57b, Moed Katan 25b, Yevamos 121a); Kiddushin 71b uses it to mark the boundary of Bavel for yuchasin, and Eruvin 22b in the laws of eruvin. Berachos 59b rules that certain stretches call for the berachah oseh maaseh bereishis, only part of the course being the original riverbed, and then expounds the Biblical Chidekel; Rava adds that the people of Mechoza are sharp because they drink the Diglat's waters. Rashi (to Taanis 24b, Moed Katan 25b, Bava Kamma 30a) states plainly that the Diglat of Shas is the Chidekel of Tanach.
The name in other languages
The Akkadian Idiqlat/Idiglat is the closest to the Hebrew. Rabbi Aharon Marcus claims it is a corruption of the Hebrew, the hard initial ches softened to an aleph and a final tav added; modern linguists instead derive it from the Sumerian Idigna, "the river that goes," adapted to Akkadian. The Arabic is dijlah (so Rabbi Saadia Gaon's Tafsir to Bereishis 2:14); Targum Neofiti to Bereishis 2:14 and the Peshitta have Tiklat, with a kuf; the Turkish is Dicle, also a given name. The Samaritan text at Bereishis 2:14 writes ha'dekel, a hei for the ches; perhaps, Rabbi Reuven Chaim Klein suggests, the Samaritans took the Masoretic ches for a typo and had the audacity to change it.
Dekel (דקל) and degel (דגל)
- Rabbi Refael Mamo ties both river-names to dekel, the palm, which grows thick along the Tigris to this day, Diglat reaching the same root through the kuf/gimmel interchange.
- The root of Diglat would seem to be ד-ג-ל, as in degel, a flag, and of ha'dekel ד-ק-ל. Rav Hirsch (to Bamidbar 1:52), without mentioning the river, notes the similarity of those two roots: a degel is a standard seen from afar, a palm a tall tree seen from a distance.
- Rabbi Reuven Chaim Klein adds that the river might connect to ד-ק-ל, and maybe even to ד-ג-ן, dagan, grain, since its water let both grow in the fertile crescent.
Tiglat-Pileser
The Assyrian king who began the exile of the Northern Kingdom is Tiglat-Pileser (Melachim II 15:29, 16:10), Tiglat-Plesser (Melachim II 16:7) or Tiglat-Pilnesser (Divrei HaYamim I 5:6, II 28:20).
- Wilhelm Gesenius, the German philologist, took the Tiglat- element as the Diglat, by the interchange of tav and dalet, and rendered the name "Lord of the Tigris."
- Modern Assyriologists have since shown that the original name was Tukulti-apil-Esharra, "my trust is in the son of Ashur," Ashur being the Assyrian nation (from Shem's son Ashur, Bereishis 10:22) and its chief deity; none of which, Rabbi Reuven Chaim Klein concludes, has to do with the Tigris.
The name Tigris, and tigras (תיגרס)
Tigris is first recorded in Greek and Latin, and philologists have long argued for a Persian origin (compare Tigranes, several Armenian kings of the Roman period).
- Some scholars trace it to Old Persian tigra-, sharp or pointed, from Avestan tighri-, arrow, which Rabbi Ernest Klein, in his etymological dictionary of English, traces to the Indo-European (s)teig-, pricking or piercing, said to be the source of English stick; this is now often taken as a folk etymology, but either way it is thematically like the Gemara's chad.
- Rabbi Aharon Marcus instead surmises that Tigris is a corruption of Diglat, l turning to r and d to t, as is apparently common in Persian, so that Tigris is the same name again.
- Abarbanel (to Bereishis 2:14) says the river is called Tigris after the tiger, tigris, both moving at speed; English tiger comes from the Latin and Greek tigris (also the Modern Hebrew word), themselves said to come from the Persian for arrow, for the way the tiger springs on its prey.
For tigras in Chullin 59b, see above.
Where the authorities disagree
Why the Torah says Chidekel and Chazal say Diglat.
- Rabbi Naftali HaKohen Katz (Kedushah U'Brachah to Berachos 59b) reads the Gemara as answering an unspoken question from the Torah's side: Kush and Ashur are given their popular names, so why does the Tigris get an obscure one and not Diglat? Because Chidekel alludes to the river's character.
- Rabbi Matzliach Mazuz, in a 1937 letter to Rabbi Chawita Kohen of Djerba (Vaya'an Shmuel vol. 12 p. 76; also Shayarei Kehunah HaChadash, Orach Chaim 47), asks from the other side why Chazal preferred Diglat, and assumes that by their time people no longer called it Chidekel, so they used the familiar name. Rabbi Reuven Chaim Klein somewhat expands this by presuming that the two names are from two languages, Chidekel Hebrew and Diglat Aramaic; and Shadal (to Bereishis 2:14) had already noted that they are cognates, the Aramaic dropping the initial ches and trading kuf for gimmel.
What "sharp and light" describes.
- Torah Temimah (to Bereishis 2:14): the water itself, sharp in taste and light, not hard on the body and weighing less than water from elsewhere (perhaps, Rabbi Reuven Chaim Klein wonders, for having fewer minerals).
- Rabbi Refael Mamo (Shevo V'Achlamah to Berachos 59b): the current, which runs fast where the Euphrates runs slow, since in Chazal's idiom whatever works fast is called sharp, as a sharp knife cuts quickly.
How the name is built.
- Rabbi Aharon Marcus (Keses HaSofer to Bereishis 2:11, Barzilai p. 127) takes Chidekel as an ancient Hebrew four-letter word, though Hebrew roots generally have three letters or fewer, and conjectures that its core is ח-ד-ק with a lamed added at the end, on the model of barzel, karsul, chanamal, arafel, carmel, chargol and givol; how he relates ח-ד-ק to the river is not so clear.
- Torah Temimah explains the Gemara's derashah from the same rarity: because four-letter roots are rare, Chazal read the name as two two-letter words.
- Rabbi Mamo takes it differently, that the base is dekel, palm, and the Gemara asked only what the prefixed ches adds, the answer being chad.
Tigras in Chullin 59b.
- Rabbi Binyamin Mussafia (Mussaf HeAruch): the tiger, so called because it runs as swiftly as an arrow; like Abarbanel, he notes that the Tigris is named for its fast current. Rabbi Reuven Chaim Klein adds that this etymology first appears in Isidore of Seville's Latin Etymologies (around the year 600).
- Dr. Alexander Kohut (Aruch HaShalem) rejects Rabbi Mussafia's reading, partly because a tiger has nothing to do with a lion and partly because in context the Gemara seems to describe a mythological animal, and identifies tigras with the martichoras, the manticore of Old Persian myth, a lion with a human face and a scorpion's tail; he implies that the name was parsed as mar ("master") plus tichoras, corrupted to tigras.
Radak on this root
Sefer HaShorashim
ד-ג-ל
The דֶּגֶל, the standard that the heads of the troops raise; and a verb comes from it, which he gives without a gloss.
The standard
דֶּגֶל מַֽחֲנֵה יְהוּדָה (Bamidbar 2:3), the standard of the camp of Yehudah, pointed בשש נקדות, with six dots. He glosses it הנס שמרימין ראשי החיילות, the standard that the heads of the troops raise.
The verb from it
דָּגוּל מֵרְבָבָֽה (Shir HaShirim 5:10), marked out above ten thousand; וּבְשֵֽׁם־אֱלֹהֵינוּ נִדְגֹּל (Tehillim 20:6), in the name of our God we will raise our banner; and אֲיֻמָּה כַּנִּדְגָּלֽוֹת (Shir HaShirim 6:4), awesome as ranks under their banners.
דֶּגֶל מַֽחֲנֵה יְהוּדָה (במדבר ב, ג), בשש נקדות. והוא הנס שמרימין ראשי החיילות. והפעל ממנו דּוֹדִי צַח וְאָדוֹם דָּגוּל מֵרְבָבָֽה (שיר השירים ה, י), וּבְשֵֽׁם־אֱלֹהֵינוּ נִדְגֹּל (תהלים כ, ו), אֲיֻמָּה כַּנִּדְגָּלֽוֹת (שיר השירים ו, ד).
Radak, Sefer HaShorashim, Berlin 1847. Public domain, digitised by Sefaria from the National Library of Israel.
Sources
Rabbi Reuven Chaim Klein, "Devarim: The Sharp River," What's in a Word?, Ohr Somayach, 2 August 2025.
Cited in the essay: Bereishis 2:11, 2:14, 10:22; Shemos 23:31; Bamidbar 1:52, 34:12; Devarim 1:7; Melachim II 15:29, 16:7, 16:10; Nachum 1:12; Daniel 10:4; Divrei HaYamim I 5:6; Divrei HaYamim II 28:20; Berachos 59b; Eruvin 22b, 57b; Taanis 24b; Moed Katan 25b; Yevamos 121a; Kiddushin 71b; Bava Kamma 30a; Chullin 59b; Bereishis Rabbah 16:4; Targum Onkelos to Bereishis 2:14 and Shemos 23:31; Targum to Nachum 1:12; Targum Neofiti to Bereishis 2:14; the Peshitta; Rashi to Shemos 23:31, Taanis 24b, Moed Katan 25b and Bava Kamma 30a; Rabbi Saadia Gaon, Tafsir to Bereishis 2:14; Abarbanel, Shadal and Torah Temimah to Bereishis 2:14; Rav Hirsch to Bamidbar 1:52; Rabbi Naftali HaKohen Katz, Kedushah U'Brachah to Berachos 59b; Rabbi Refael Mamo, Shevo V'Achlamah to Berachos 59b; Rabbi Matzliach Mazuz, Vaya'an Shmuel vol. 12 p. 76, and Shayarei Kehunah HaChadash, Orach Chaim 47; Rabbi Aharon Marcus, Keses HaSofer to Bereishis 2:11 and Barzilai p. 127; Rabbi Binyamin Mussafia, Mussaf HeAruch; Dr. Alexander Kohut, Aruch HaShalem; Josephus, Antiquities 1.1.3; Rabbi Levi ben Avraham; Rabbi Nissim of Marseilles; Isidore of Seville, Etymologies; Wilhelm Gesenius; Rabbi Ernest Klein's etymological dictionary of English.