TT #308 · Parshas Tazria · Aliyah 7 · Passuk 59
English: This is the law of the lesion of tzaraas in a garment of wool or linen, in warp or woof, or in any leather article, to declare it clean or impure.
Chabad.org — Chumash, English translation + Rashi for Vayikra 13:59
Torah Temimah cites Moed Katan 7b for deferring skin-affliction examinations during a festival.
E-Daf — Moed Katan 7b · Shas.org · Sefaria — Moed Katan 7b, source text and translation
English: Lesions are not examined during a festival, either to ease the ruling or to make it stricter, as the verse says, “to declare it pure or impure.”
Textual derivation
Priestly examination is deferred during a festival rather than being conducted to make a ruling lenient or strict.