תפלה ו
תפלה ו
Source: https://ajew.org/reader/likutay-halachos/1/37

Segment 3
HE:
הלכה ו אות א שנכללת בהלכות ברכת השחר

EN:
The parchment of Tefillin must be from the hide of a kosher domesticated animal, wild animal, or bird, as it says: "L'ma'an…" — from a species that is permitted to your mouth, etc.