TT #111 · Parshas Shemini · Aliyah 5 · Passuk 8
Chabad.org — Vayikra Chapter 11 with Rashi
English: You shall not eat of their flesh, and you shall not touch their carcasses; they are impure for you.
Sifra (Toras Kohanim), Shemini, Chapter 3.
Sefaria — Sifra, Shemini, Chapter 3
טְמֵאִים הֵם. הֵם – פְּרָט לְשֶׁאֵין בָּהֶם בְּנוֹתֵן טַעַם.
Textual exclusion — The word “they” excludes mixtures lacking the prescribed taste from this particular rule.
The word הם excludes cases in which the prohibited substance contributes no discernible taste.