Rashi on Deuteronomy 24:8/רש"י על דברים כ״ד:ח׳

1השמר בנגע צרעת TAKE HEED IN THE AFFLICTION OF LEPROSY — take heed that you pluck not out the symptoms of uncleanness (cf. Leviticus ch. XIII.), nor cut out the leprous spot (Makkot 22a).

2ככל אשר יורו אתכם ACCORDING TO ALL THAT [THE PRIESTS …] SHALL TEACH YOU — whether to place the leper in quarantine, or to declare him definitely unclean or clean.