I. Detailed Study of the Talmudic Description of the Tekhelet-hillazon

Which species of marine shell-snail is meant by the description thus recorded in the Talmud and the Baraitha d’Tzitzit?

Before we attempt answering the question, it is of course absolutely essential to ascertain the exact import of each of the three elements which constitute the description.

(a) presents no serious difficulties: it refers to a dark blue or dark violet-blue resembling the colour of the Mediterranean or of the clear cloudless Palestinian sky in bright sunshine

(b) offers considerable difficulty. What is the exact delimiting force of this likening of the form of the Tekhelethillazon to a fish? In other words which species or genera of marine shell-snails are meant to be excluded by (b)?

It is clearly of vital importance to determine first of all the scope of application of the term dag (fish) in the Talmud. With reference to the concept “fish” in ancient classical literature Dr. L. Germain in reply to a question addressed by me says: 


“Among the ancients, all animals that live in the sea were designed under the name of Pisces. Thus Pliny, after saying Piscium quidam sanguine carent192 which is an assertion at least bizarre, adds that there are 3 categories of Pisces: peas, soft (Mollia); Crustaceans (Crustacea); and testaces (testacea).

Aristotle is the only ancient author who clearly separated molluscs from fish. Among the Moderns, the term fish is restrictive and applies as you only know to marine or freshwater vertebrae whose type is, for example, salmon by eliminating all Crustaceans, Molluscs, Cephalopeds and others that are Invertebrates. “

“Chez les anciens on designait sous ce nom de Poissons tousles animaux qui vivent dans la mer. Ainsi Pline, après avoir dit Piscium quidam sanguine carent1  ce qui est une assertion au moins bizarre, ajoute qu’il y a 3 categories de Poissons: les Pois, mous (Mollia); les Crustaces (Crustacea); et les Testaces (testacea).

Aristote est le seul auteur ancien ayant nettement separe les mollusques des poissons. Chez les Modernes, le terme poisson est restrictif et ne s’applique comme vous savez qu’aux vertèbres marins ou d’eau douce dont le type est, par exemple, le saumon en eliminant tousles Crustaces, Mollusques, Cephalopèdes et autres qui sont des Invertèbres.”


The Tanaites, as is clear from their likening of the figure of the hillazon to that of fishes, were not in this instance behind Aristotle. The Mishna (Kelim X, 1) distinguishes “fishes” (dagim) and “beasts of the sea” (hayyot hayam) 2עצמות הדג… עצמות חיה שבים

  1. Elijah Wilna (ib. אליהו רבה) strikes out חיה שבים on the ground that all marine creatures whatever their form are comprised in the appellation dag:

ול״ג עצמות חיה שבים כל שבים מין דג הוא כל דמות שתהיה לו

There is, however, no real ground for questioning the correctness of the text; characteristic (b) in the description of the hillazon shows clearly the inexactness of R. Elijah Wilna’s sweeping generalisation. I doubt if the assertion really emanates from the celebrated “gaon of Wilna.”

From the sporadic allusion to the nature and characteristics of fishes it is difficult to evolve a more or less clear idea of the type dag (fish) according to the Talmudic conception.3

Maimonides distinguishes two classes of aquine creatures:

  1. dagim (fishes)
  2. sheretz hamayim (שרץ המים), i.e., “creatures not of the shape of dagim.”

איזהו שרץ המים אלו הבריות הקטנות כמו התולעים והעלוקה שבמים והבריות הגדולות ביתר שהן חיות הים כצצות של בבל 4כל שאינו בצורת דג לא דג המא ולא דג טהור כגון כלב המים והדלפון והצפרדע וכיוצא בהן

This is not very helpful. It would appear, however, that in his conception the Gasteropoda and Cephalopoda, at least are comprised in the term dag. It is significant that in his description of the Tekhelet-hillazon Maimonides does not reproduce the Talmudic statement that the hillazon is like unto a fish, but says plainly that it is a species of fish. Nachmanides5 seems to hold that all marine creatures furnished with legs in the manner of terrestrial animals are excluded from the category of dag.

Would it follow according to Nachmanides that (b) should be understood as excluding the Gasteropoda to which belong the genera Murex Purpura and also Janthina? Is then the hillazon-shel-Tekhelet to be sought, according to Nachmanides, exclusively among the Cephalopoda? I very much doubt whether such is the import of (b). It should also be noted that דומה (domeh, “is like”) is a relative term. It is scarcely possible to determine the degree of similarity demanded by (b).

Our search for the hillazon shel Tekhelet is thus hampered by an obscurity which is hard to dispel.

The last element also offers certain difficulties. ועולה אחד לשבעים שנה “it comes up once in seventy years.” “oleh” (עולה) has been taken by some as meaning that the hillazon-shel-Tekhelet is not fished but is caught on the cliffs and rocks when it creeps up from the sea. This is, however, not warranted by the verb alah עלה. Oleh may well mean “is fished.” Sabbath 74b refers to the manipulation of nets in fishing the hillazon in connection with the preparatory work for the construction of the Tabernacle.

Rashi explains the reference as applying to the Tekhelet-hillazon. But the Talmud has in view the Argaman-hillazon, of both species. Rashi reflects his interpretation of Argaman as only a colour designation with no restriction as to the origin of the dyestuff producing the particular colour.

Sabbath 26a referring to fishermen engaged in the catching of hillazon may likewise apply either to both species or to Argaman alone. It might be argued that since in the time of Raba or R. Ilai (to either of whom is ascribed the reference to the fishing of the hillazon quoted Sab. 74b) Argaman had long disappeared from religious use,6 the Tekhelet rather than the Argaman species would be uppermost in the minds of students of the Torah when speaking of hillazon in connection with the Tabernacle or Temple; if therefore the Tekhelet-species were not secured by means of fishing, Raba or R. Ilai would have thought it necessary to add some such qualification as shel Argaman to hillazon. The argument, however, hardly possesses sufficient cogency to serve as a basis for our inquiry.

(c) “… once in seventy years”. This appears very baffling on the face of it but in reality the statement should present no insurmountable difficulty. When in 1887 a certain R. Gershon Enoch Leiner embarked upon a hard search after the Tekhelethillazon he found his way blocked by (c). Science knows nothing of such a septuagenarian “appearance” of any of the denizens of the sea.

Apart from that it is not stated what date is taken as a starting point from which the periodicity is to be counted nor is there a record of the “appearance” of that rare species at a definite point of time which might serve us a base of calculation. Leiner7 contends that though its “appearance” en masse would occur only once in seventy years it could be found in small quantities at any time.

In reality, however, the expression is simply an arithmetic hyperbole of the kind which is pretty common in the Talmudim and Midrashim. “Once in seventy years” amounts to saying that the species is caught at long intervals of time. The value of (b) is rightly estimated in his edition of the Baraitha d’Tzitzit.8

.בגמרא שם הגירסא) שבעים שנה והוא אגדה. ובשבת אמרו לכרמים וליוגבים ומזה מוכח ר״ע שנה לאו דוקא)

His argument, however, from Sabbath 26a is pointless because the reference in that passage may be to the Argaman-species. Nebuzzadan would be as much interested in the fishing of the Argamanhillazon as in that of the Tekhelet species. Perhaps his interest would be centred in the former rather than in the latter species.

Owing to the absence of a distinct mention in Talmudic literature of hillazon in connection with Argaman, Jewish writers, generally speaking, laboured under the misconception that Argaman was not of hillazon origin.

The Baraitha d’Tzitzit has “once in seventy years” which being the more sober number is probably the original one. “Seven years” is likewise a round number; strict periodicity is hardly to be thought of.

It should be carefully noted that the Talmud does not attribute the expensiveness of Tekhelet to the fewness of the individuals constituting the Tekhelet-species but to the rare “appearance” of individuals belonging to that variety of sea-snail. When the “appearance” does take place it may be a very numerous one.



  1. Pliny, ibid., book IX, ch. 44.
  2. Sifra,מצורע; שמיני
  3. Cf. ירושלמי: כלאים, פרק א ,הלכה ו״; בכורות ח ע״א; עבודה זרה מ ,ע״א

    מררש רבא; בראשית, פרשה א; כלים פרק י,; משנה א״; חולין קי״ב ע״ב; נדה מ ע״א.

  4. .רמב״ם כ״ב הלכות, מלאכות אסורות
  5. Nachmanides, Comm, on the Pentateuch, sect. שמיני
  6. Since the destruction of the Temple
  7.  לינר גרשון חנוך, שפוני סמני חול. וארשא תרמ״ז(1887) ע׳4א׳
  8. שבע מסכתות קטנות ירושלמיות … (עורך) רפאל בן קיר כה״ם פראנקפורט א״מ תרי״א (1851) .