TT #284 · Parshas Tazria · Aliyah 7 · Passuk 52
English: He shall burn the garment, the warp or woof of wool or linen, or any leather article in which the lesion is found, for it is malignant tzaraas; it shall be burned in fire.
Torah Temimah cites Sifra (Toras Kohanim) for excluding decorative trims from the prescribed burning rule.
Sifra — Vayikra 13, Midrash Sefer
English: Why does the verse specify wool or linen? To exclude decorative hems or trims from the garment that is burned.
Textual derivation
The decorative hems or trims attached to a garment are excluded from the specific command to burn the garment itself.