[י"ב תמוז, ה'תשל"ג]
שלום וברכה!
. . .
במענה
למכתבו - עליו להעשות בקי בהלכות תפילין הצריכות, ובב' וג' מאמרי חסידות (שע"ד ענין תפילין).
Yud-Beis Tammuz, 5733.
Shalom u'Vrachah!
... In response to your letter — you should become proficient in the necessary laws of tefillin, and in two or three Chassidus discourses (Shaar Daled on the subject of tefillin).
Summary
The Rebbe teaches that one should master both the practical laws of tefillin and deepen their understanding through studying relevant Chassidus discourses, integrating halachic knowledge with inner meaning.