TT #278 · Parshas Tazria · Aliyah 7 · Passuk 51
English: The priest shall examine the lesion on the seventh day; if it has spread in the garment, warp or woof, or leather article, the lesion is malignant tzaraas; it is impure.
Torah Temimah cites Sifra (Toras Kohanim) for including hides used for tents among materials subject to the rule.
Sifra — Vayikra 13, Midrash Sefer
English: The phrase “for every use made of leather” includes hides used for tents.
Textual derivation
The garment-tzaraas rules extend to leather hides used for tents.