Thursday, January 26, 2017

Are there standard sizes for tefilin batim (leather cases/housings) today?


I just looked down at the little plastic cover on my arm-tefilin and it had the number 4 on it. I assume that's a size ... while tefilin must be square, there are definitely a variety of sizes out there. Are there now some standards? Does anyone know what they are? E.g. "size 4 is 1.5 inches" or something?



Answer



Mine says 35, and by measuring it, that's in millimeters (the bayis, not the titura). So yours is probably 4 cm = 40 millimeters.


(I've heard this size called "daled al daled." I used to think that meant four etzbaos, but that's definitely not the case - an etzba is 20 mm according to R' A.C. Naeh, and about 26 mm according to the Chazon Ish, so tefillin 4x4 etzbaos would be huge.)


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