TT #271 · Parshas Tazria · Aliyah 7 · Passuk 49
English: and the lesion is greenish or reddish in the garment, leather, warp or woof, or any leather article, it is a lesion of tzaraas and shall be shown to the priest.
Torah Temimah cites Sifra (Toras Kohanim) for the wording printed in the current Sifra unit; the Chafetz Chaim explains that the exclusion concerns the garment’s edge threads.
Sifra — Vayikra 13, Midrash Sefer
Wikisource — Chafetz Chaim on Sifra, chapter 14
English: “In a garment”—but not in its edge threads. The Chafetz Chaim explains that if the lesion appears on the threads remaining at the garment’s edge, those threads are impure while the garment itself remains pure.
Textual derivation
The Sifra distinguishes the garment itself from threads remaining at its edge; those threads are treated separately, like warp and woof.