There are many Compelling arguments to support Techelet, although it's not yet universally accepted.

A friend of mine bought P'til Tekhelet Murex techeiles, and went to his rabbi (who I know and respect) to ask for advice on how to tie it, and his rabbi told him "Don't."

While I'm pursuing the answer to the question through other means, what possible reasons are there to say not to wear techeiles? Let's say that Murex is not the chilazon, and we have some strings that have been dyed blue for no reason. What problem could there be in attaching those strings to my tzitzis?


You ask, "let's say that Murex is not the chilazon, and we have some strings that have been dyed blue for no reason. What's the problem with that?" (my emphasis)

If there really is no reason to dye them blue whatsoever, then doing so would be a violation of the Shulchan Aruch (9:5), who says that careful people use strings of the same color as the garment, and we use a white garment, and the Rama there who notes that the custom is to use white (this is pointed out by R. Elyashiv in his collected teshuvos, 1:2). While the Chazon Ish (3:25) and the Radziner Rebbe (Ein HaTecheiles 1:40:1) don't think that this applies to all of the strings, many poskim seem to assume that all four strings should be white, in the absence of techeiles.

This stringency, however, would not be enough of a reason to say not to use techeiles if there's any reason at all to assume that it might be correct.

Let's assume, then, that it's a matter of doubt, and (the assumption is) that one should be stringent as ספק דאורייתא לחומרא. Why not dye them with the new blue?

  1. A halachik reason: Many (including R. Moshe Shternbach, Teshuvos V'Hanhagos 1:26 and 4:5) have written that placing something extra on tzitzis with the intent to possibly perform a mitzvah, even out of doubt, is violating the prohibition of bal tosif. (This is the indication of the Gemara in Zevachim 81a, and though the Ritva Sukkah 31b says otherwise, there were many poskim throughout history on both sides of this question).

  2. A kabbalistic reason: There are apparently kabbalistic reasons to avoid using real techeiles strings nowadays anyway, which was the objection of R. Yisrael Yehoshua Trunk (Shu"t Yeshuos Malko O.C. 1-3). (It's hard for this to be understood literally as Kabbalah can't uproot a biblical obligation. Rav Asher Weiss suggests the intention might be more along the lines of: kabbalah tells us that the true techeiles has been lost and so anyone who thinks they are wearing it nowadays must be donning a spiritually destructive fake.)

  3. A meta-halachik reason: I've been told by a posek that he was worried that if we come to dye them blue from the murex out of doubt, then future generations might mistakenly believe that there's a tradition that this is the proper chilazon. This is problematic because (1) it is a 'ziyuf hatorah', a misrepresentation of the Torah, which the Maharshal (Yam Shel Shelomo B.K. 4:9) thinks is so terrible as to be worth dying for (2) if Eliyahu does come and provides us with a different snail, things could get very awkward and we might not know what to do.

If you are going to wear it in public, then we can add that R. Shternbach (ibid.) prohibits wearing blue tzitzis in public because of the prohbition of 'lo tisgodedu', of making apparent divisions in halakhic practice among different people.

Of course, the assumption above that there is a formal halachik doubt here is debatable as well. R. Shternbach (ibid.) writes that something without a tradition cannot even be considered a safek. Also, R. Soloveitchik (Shiurim L'Zecher Abba Mori, pg 228) as well as several others quote the Beis Halevi (though there is some debate if he actually said this) as saying that something that has been lost to tradition is equivalent to a tradition that something has been lost; meaning, it's as if there's a mesorah not to use anything as blue until Eliyahu or the like can reinstate it from their own mesorah, not just from arguments.

Additionally, it isn't at all true that the evidence is 'compelling' to everyone that the murex trunculus is the correct fish for dying techeiles. There are good answers to this question, both in terms of archaeological evidence and halakhic literature regarding the identity of the chilazon. Rav Asher Weiss and Rav Shlomo Miller, both widely accepted poskim, do not think that there is enough evidence to even raise a doubt, and discourage the use of techeiles (without really providing an answer to this question). For many people, the fact that these poskim are unconvinced is enough of a reason not to view it as a doubt. (The list of poskim that have discouraged it extends far beyond these, though of course it isn't unanimous, and those who do wear techeiles have answers to the above issues. You asked about the potential downsides).

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  • I wonder if having stripes on the Tallis (as many ashkenazim do) would be enough to allow for multicolored strings (accd to the rambam). I suspect it would only help if the stripes reached all the way to the corner itself (something I've never seen done, but probably could be arranged without too much complaining from the manufacturers or the 'gedolim'). – Double AA Jan 19 '15 at 17:46
  • @DoubleAA I've asked a Rav before about the stripes, and he said that it only matters which single color is of the majority of the beged. But he didn't have a source and i haven't looked into it – הנער הזה Jan 19 '15 at 18:17
  • @DoubleAA also re #3: apparently R. Seriah Deblitzky feels the same way. (Note that he quotes Wikipedia which in turn quotes that very forum... almost an example of this but not quite) – הנער הזה May 3 '16 at 2:54
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    (You may be interested in Maharil (5:2) וסברא הוא דשמא יחזור דבר לקילקולו שיהא תכלת מצוי, כ"ש למאי דכתב סמ"ג דאותו דג חלזון הוא בים המלח וכתב סימנין, בקל היה לעשות תכלת seems no Mesorah is needed (or that Mesorah from written texts is sufficient).) – Double AA Dec 9 '16 at 3:44

There is a tshuva from Reb Elyashiv where he says either the tradition of what techeiles is was lost, or it wasn't lost and there was some reason the Rabbis allowed its disuse. He says we should not change as this would qualify as a minhag and al titosh toras imecha.

I have another idea that I've mentioned to some people that they've appreciated. Let's see what the Mi Yodeans think.

The gemara in Bava Metzia 61b reads like this. Rava said why did the Torah mention Yetzias Mitzraim by Ribis by tzitzis and by weights? Hashem said I am the one who recognized in Egypt between the drop who was of a bechor and the drop that was not of a bechor. I am He who will get back at someone who uses a nonjew as a pretext and lends his money to a Jew with ribbis, and from someone who keeps his weights in salt, and someone who hangs Kala Ilan, fake techeiles, on his clothing.

The idea of the first two is that this person is gaining monetarily from his deceit. The case of hanging fake techeiles also can be explained this way, as the Rosh in fact did see there #4 'one who hangs Kala Ilan on his clothing to sell in place of Techeiles'.

However Tosafos seems to understand differently. Tosafos points out 'even though this is a transgression his mitzvah of tzitzis, even still the passuk is needed so that he will be transgressing from when he hangs those strings.' Tosafos is dealing with the actual fulfillment of the mitzvah, not the issue of stealing. The fact that within the parameters of the mitzvah a person will transgress simply by putting fake techeiles on his clothing, even before wearing them, is a good reason not to put techeiles on which might be fake.

One can claim that this passuk is only talking about someone who puts fake techeilas knowingly, which would then have no bearing on today's situation where it is put on out of doubt, but that would be an unprecedented novalle.


Controversy aside as to what the techeiles dye really is, there is good reason not to reinstate it. Rabbi Cohen writes in Dose of Halacha:

the Beis Halevi (R’ Yosef Ber Soloveitchik, 1820-1892) maintained that as the techeles has been lost from our mesorah, tradition, it should not be reinstated, irrespective of the evidence.

He continues by explaining that there is a precedent for this among other mitzvos, such as Birchas Koahanim.

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    What's the good reason? – ertert3terte Jan 18 '15 at 23:31
  • Why can't he wear it without reinstating it? – Double AA Jan 18 '15 at 23:34
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    Why doesn't that site cite how it knows what the Beis Halevi thought about that? (Hint: he never actually wrote that anywhere and in fact wrote the opposite. judaism.stackexchange.com/a/8363/759) – Double AA Jan 18 '15 at 23:42
  • I don't know. I believe the Briskers all believe that side of the story, though think the Radziner Rebbe wrote something else from the Brisker.. – Zvi Jan 18 '15 at 23:43
  • Just saw your comment - thanks for that link! Any idea where it is in his book? – Zvi Jan 18 '15 at 23:45

I was thinking, Rashi says at the end of parshas Shelach that the reason the torah mentions yetzias mitzroyim in the parsha of tzitzis is because just like HKBH was mavchin bein tipah shel b'chor l'tipa sheino shel b'chor, so too He knows the difference between one who puts on real techeiles and one who takes dye from a tree and calls it techeiles. It could that that is the risk in wearing sofek techeiles, because apparently there is an issue with wearing something that you are considering techeiles that may not really be true techeiles.

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    "apparently there is an issue" I see no evidence for that. It just says God won't be fooled into thinking you are wearing techeiles, not that he will be angry with your or punish you or that you are doing anything wrong. Moreover, as long as you also think it's a safek there's no way it would be a problem since you wouldn't even be trying to trick anyone. – Double AA Jun 20 '17 at 14:29
  • Regarding your first point, I think the mashmaus from Rashi is that Hashem is not happy when one does it, because otherwise, what is the point of Rashi's comment? That Hashem knows the difference between real techeiles and fake techeiles? Of course He knows the difference. The point Rashi seems to be making is that one shouldn't do this because it is not right. Your second point is kind of what I was thinking. It could be that, assuming Hashem is not happy about what this person is doing, it would only be a problem if he does it b'meizid, and he uses a dye that he knows is not techeiles – anonymous Jun 21 '17 at 14:25
  • (continuing my point abouve) But if he uses something that is a sofek (like today's techeiles) it would not fall under this issue – anonymous Jun 21 '17 at 14:28
  • No, you can say even more that, even if he purposely uses fake Tekhelet with no intention of tricking anyone (because he likes the color or it's all he has or whatever), it's also ok. The key here isn't that it's a safek but that no one is trying to trick anyone – Double AA Jun 21 '17 at 14:29

Surely it is obvious that if we knew for sure that this was not the real techeiles, then it would be a very bad thing to use it. It would be like if you can't get an esrog, using a lemon instead. As the gemara in Sukkah 31b says about that case, "It's obvious you shouldn't do that! No, you might say, do it in order that the mitzvah of esrog not be forgotten. The mishnah comes to say, it will lead to more damage, as people will be pulled into using it instead of the correct species." And to me this case seems much more obvious. At least there everyone knows that a lemon is not an esrog; here the confusion is built in.
Since that is so, it just becomes a question of how good is the evidence for and against, which is something that individual poskim will see differently.

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    "Since that is so, it just becomes a question of how good is the evidence for and against" That's not true. As Matt wrote "This stringency, however, would not be enough of a reason to say not to use techeiles if there's any reason at all to assume that it might be correct." In other words, once you're evaluating the worth of the different bits of evidence, this becomes irrelevant. It's only relevant to people who think there is literally no evidence at all (apparently such people exist, to my disbelief) – Double AA May 23 at 20:36
  • @DoubleAA "This stringency" - Matt meant, we prefer to use white! That is nothing compared to the very serious problems that result from people having a tradition to use the wrong dye. Whole different league. – MichoelR May 23 at 20:46
  • Severity is not the issue here. Chazal are not gozer on a safek lemon. You can repeat Matt's item 3 as a meta halachic reason, but that's not the formal argument from the Gemara you cite. You admit this is only relavent if "if we knew for sure" – Double AA May 23 at 20:52
  • 'You admit this is only relevant if "if we knew for sure"' No, I brought a case where the answer is easy. One can use that case to understand nearby cases, such as where we are almost sure. – MichoelR May 23 at 21:01
  • Let us continue this discussion in chat. – MichoelR May 23 at 21:16

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