Fifty years ago, at the Purim farbrengen of 5736 (1976), the Rebbe introduced a revolutionary practice: that every bar mitzvah bochur should don Rabeinu Tam tefillin daily.

Until that time, chassidim generally wore Rabbeinu Tam’s tefillin after marriage, or when they turned eighteen and had substantially grown in their avoda. Yet at that Purim farbrengen of 5736, the Rebbe revolutionized the custom to wrap a second pair of tefillin.

Unfortunately, there were those who attempted to challenge the minhag as unnecessary or inapplicable.

Rabbi Moshe Wiener of Crown Heights, executive director of the JCCGCI and author of the encyclopedic work Hadras Panim Zakan on the significance of growing a beard, shares his personal story with the Rebbe and the guidance that ultimately led him to compile a concise halachic monograph directly addressing the key questions and challenges regarding the practice of Rabbeinu Tam tefillin.

Notably, his booklet, entitled Be’Inyan Hanachas Tefillin d’Rabbeinu Tam – Ta’anos u’Ma’anos, was recommended by the Rebbe to a rov who had approached him with concerns about the custom.

The booklet was prepared specifically to strengthen understanding of the topic, presenting the major questions alongside well-sourced responses. It offers readers a structured, source-based, and intellectually honest presentation, making it valuable for rabbanim, educators, and thoughtful laypeople alike.

“During my years as a talmid in Mirrer Yeshiva on Ocean Parkway,” Rabbi Wiener relates, “I would often travel to the Lubavitcher Yeshiva on Ocean Parkway to attend the deep shiurim of R’ Yoel Kahn, together with bochurim from the kvutza who were serving as shluchim of the Rebbe to strengthen and uplift the yeshiva.”

As his friendship with the Lubavitch bochurim developed, he became aware of the custom among Lubavitcher bochurim to ask the Rebbe, upon turning eighteen, whether they should begin putting on Tefillin d’Rabbeinu Tam.

Having already passed that age, he decided to bring the question to the Rebbe at his next yechidus, which took place in connection with his birthday. The Rebbe’s response was encouraging and positive.

At the same time, with characteristic sensitivity and wisdom, the Rebbe added that he should put on the Tefillin in a private setting – such as a classroom or dormitory room – so that it would not appear as though he were introducing new minhagim within the environment of Mirrer Yeshiva.

(This was, of course, before the Rebbe later emphasized publicly the universal importance of wearing Rabbeinu Tam Tefillin.)

From the very next morning, the matter became personal and real.

“Each day, I would borrow a pair of Tefillin d’Rabbeinu Tam from one of the kvutza bochurim at the Lubavitcher Yeshiva until the pair I had ordered was completed. When my own Tefillin finally arrived, I began bringing them daily to Shacharis at Mirrer Yeshiva, carefully wrapped in a simple brown paper bag.”

After davening, he would quietly enter the room of the Rosh Yeshiva, with whom he had a close relationship, and whose family was close with his own. There, he would put on Tefillin d’Rabbeinu Tam, often in the Rosh Yeshiva’s presence.

“Years later, the Rebbe suggested that I prepare a publication about Rabbeinu Tam Tefillin – a guidance that I fulfilled only partially with this kuntres.”

The booklet is structured as a series of six thematic “claims and responses,” each engaging a central issue in the debate:

1. Historical origins of the dispute between Rashi and Rabbeinu Tam regarding the order of the parshiyos in tefillin, arguing that multiple traditions already existed in earlier generations and that both approaches have deep roots in classical sources.
   
2. The claim that tefillin found at the grave of Yechezkel support only Rashi’s view, which the author challenges by demonstrating that such findings cannot conclusively establish normative halachah.
   
3. The meaning of passages from the Zohar often cited to argue that only one set of tefillin is required; the work shows that authoritative manuscript versions, as well as leading commentators, understand the Zohar as supporting the spiritual necessity of both.
   
4. The position of later halachic authorities, including the Aruch HaShulchan and the Vilna Gaon, analyzing their arguments with respect, while also presenting counter-evidence from other major poskim and kabbalistic sources.
   
5. The concern of “yuhara” (ostentation) cited in the Shulchan Aruch, with the author demonstrating that in contemporary practice – where many frum Jews wear Rabbeinu Tam tefillin – this concern does not apply in the same way.

The booklet concludes that, particularly in light of the teachings of the Arizal and many later authorities, wearing both Rashi and Rabbeinu Tam tefillin is an important minhag grounded in serious sources and longstanding tradition.

“The booklet is only partially complete,” Rabbi Wiener says. “I daven that I may one day be zoche to properly expand the kuntres in line with the Rebbe’s wishes.”

The publication is available on Amazon and can also be downloaded here at no cost.