1. Minimum Length of Tefillin Straps
The discussion begins with the concern that the straps of the tefillin—phylacteries—should not touch the ground. This requirement suggests that the straps are of a significant length, enough that one must be careful to prevent them from falling and making contact with the floor.
2. Implication for Strap Length
From this, it is implied that the proper custom is for the straps to be quite long. The need to actively protect them from touching the ground indicates that they extend well below the arm or head, perhaps reaching almost to the ground itself.
3. The Rebbe’s Guidance on Strap Length
The Rebbe appears (?) to support this approach, implying that ideally, the straps should be long enough that one must take care they do not fall and touch the ground. This would mean allowing them to hang down substantially, nearly reaching the floor, in accordance with this understanding of proper tefillin practice.