Rabbenu Tam Tefillin
This is the approved revision of this page, as well as being the most recent.
Wearing Rabbenu Tam Tefillin
- Pious individuals have the practice of wearing both Tefillin of Rashi and Rabbenu Tam, with no bracha when putting on the Rabbenu Tam. 
- Unmarried individuals should not wear Tefillin of Rabbenu Tam unless they know that they are capable of having pure thoughts for as long as they are wearing Tefillin. 
- No beracha is recited when putting on tefillin of Rabbenu Tam. Nevertheless, one should not speak between the shel yad and the shel rosh. 
- If one mistakenly put on Rabbenu Tam first, some poskim say to recite a bracha when putting on the Rashi Tefillin. 
- The Rashi and Rabbenu Tam Tefillin should be placed in separate bags. 
Arrangement of Paragraphs
- There is much discussion among the rishonim (early authorities) about the order in which the biblical passages should be written in the arm and head Tefillin. The rabbis most famous for this dispute were Rashi and his grandson Rabbenu Tam. Rashi held that the order is: Kadesh Li (Shemot 13:1-10), VeHaya Ki Yeviehcha (Shemot 13:11-16), Shema (Devarim 6:4-9), VeHaya Im Shemoa (Devarim 11:13-21). Rabbenu Tam held that the last two passages were switched (thus making the following order Kadesh Li, VeHaya Ki Yeviehcha, VeHaya Im Shemoa, Shema). The custom of the world is to follow Rashi's opinion. 
- Ten Minute Halacha: Rabeinu Tam Tefillin by Rabbi Aryeh Lebowitz
- Order of Parshiyos in Tfillin: Rashi and Rabbeinu Tam by Rabbi Zvi Sobolofsky
- Kitzur Shulchan Aruch of Rav Rephael Baruch Toledano, siman 10, the order of the donning, seif 2. Shulchan Aruch 34:2-3 rules that that the especially pious should wear both sets, but added that only one commonly known to be especially pious may do so, so as not to appear as arrogant in one's piety. However, Halacha Brurah (Rabbi David Yosef, 34:1) writes that since it has become the practice of many common people to wear both Tefillin of Rashi and Rabbenu Tam it is not considered an issue of arrogance to wear both pairs of Tefillin. Aruch Hashulchan 34:5 agrees. Sh"t Yabia Omer OC 3:4 writes that if one has this stringency he should remove the Rashi and place the Rabbeinu Tam before the kedusha of "uva litzion".
- Halacha Brurah 34:2. Chacham Ben-zion Abba Shaul Sh"t Or Litzion 2:13:11 also writes that Sephardim should only wear Rabbenu Tam Tefillin after marriage. Divrei Yatziv 42 and Mishneh Halachot 6:12 agree
- Sh"t Yabia Omer 3:3
- Ben Ish Chai Vayera 24. Rav Ovadia Yosef in Halichot Olam volume 1 page 26 says that this is only if the person has prayed something in between but if he remembers immediately no bracha should be recited.
- Kitzur Shulchan Aruch of Rav Rephael Baruch Toledano, siman 10, the order of the donning, seif 5
- Shulchan Aruch 34:1, Halacha Brurah 34:1, Kitzur Shulchan Aruch of Rav Rephael Baruch Toledano, siman 10, miscellaneous laws (of tefillin), seif 2