I am tying my tekhelet according to the Rambam and was wondering if I have to tie 13 chulyot, or can I tie any number of chulyot between 7 and 13. I would find that 10 chulyot would also be very symbolic.
The Gemara (Men 39a) clearly states one should not make less than 7 chulyot and
one should not make more than 13 chulyot (so too the Rambam [Hil. Tz. 1:8]), which seems to imply any number in between is acceptable. On the other hand the Gemara clearly states that the reason for 7 is to symbolize the 7 heavens and the reason for 13 is to symbolize the 7 heavens and the 6 spaces in between. So, if you don’t do 7 or 13, you lose the “heavens” symbolism. And indeed Rashi (ibid., s.v. “shisha”) says that the symbol of the heavens is what is critical about tekhelet in that it is likened to the heavens (so too Tos., ibid., s.v., “lo yifhot”). In consonance, the Mordechai (Pesachim, Tosefet Maarvei Pesachim, 611) states that one must do 7 and if he started doing more, then he must do 13, such that one either does 7 or 13 but nothing in between, lest the symbolism of the heavens be lost. So too the Binyamin Zeev (192) says must do either 7 or 13 to maintain the “heavens” symbolism. The Ritva (Pes. 104a, s.v., “veha”) quotes the Rosh who uses this statement in Men. 39a to prove that when the Gemara says “don’t do less”, “don’t do more”, the intent is do exactly the numbers given (i.e., in our case either 7 or 13 but nothing in between).
Only the R. Avraham ben HaRambam (Hamaspik L’Ovdei Hashem, ch. 33) says that though 7 is the ideal, one can use any number between 7 and 13. I would be hesitant to apply his opinion, for though it is true enough that 10, as you propose, is a number laden with symbolism, nevertheless most opinions hold that you would be replacing the originally intended “heavens” symbolism. And furthermore “10” has its problems since the first thing that comes to mind are “the Ten Commandments” for which there were historically great philosophical fights in over emphasizing the 10 commandments to the detriment of the 613.
– Mois Navon.