TT #224 · Parshas Shemini · Aliyah 7 · Passuk 38
Chabad.org — Vayikra Chapter 11 with Rashi
English: “It is impure for you”: “for you” includes handles and other parts used for your needs.
Chullin 118a.
E-Daf.com — Chullin 118a (Tsurras Hadaf)
Textual inclusion — The Chazal derives the stated rule from the wording and structure of the verse.
The word לכם extends the rule to useful attachments.