Section: Shabbos   Category: Minhagim
Challos For Shabbos - 12 Is The Magic Number
The Din of the gemara is to make HaMotzi on Lechem Mishna or two challos by each Seuda of Shabbos.  The Zohar in Parshas Pinchos says that you should have 4 challos by each of the three seudos for a total of 12.  The Elya Rabba brings from the Shela HaKadosh that at the night meal you should have 12 challos, by day 8, by Seuda Shlishis 4, and by Melava Malka 2 for a total of 26, which is the gematria of the Shem Hashem.  The Be'er Heitev brings from the Arizal to have 12 at each seuda as a remembrance for the 12 Lechem HaPanim that were eaten each Shabbos in the Bais HaMikdash.

The Elya Rabba says that you should not use 12 challos unless you understand Kabbala very well.  The Shaarei Tshuva argues and says that even if you don't know the secrets behind it, you may do it anyway if you do it with a pure heart.  

The Shineveh Rebbe said in the name of the Chozeh of Lublin that there should be at least one person in each city that has 12 challos, and the rest of the people could use only 2 challos.  Even the two challos, says the Shineveh Rebbe, represent 12 since they are bake in shape of a Vav which is the equivalent of the number 6 and there are two challos totaling 12.  According to this, says the Likutei Maharich, the challos should be arranged side by side in their length and not in their width so that they actually resemble two letter Vavs.

Another minhag is to braid the Challos with six braids so that the two Challos contain 12 braids.  It is brought from the Alexander Rebbe that he joked that he doesn't need 12 challos like his Rebbes because a Yid (gematria 10) and his two challos equal 12. (See Minhag Yisroel Torah OC 274)