וְאִם־תַּחְתֶּ֜יהָ תַּעֲמֹ֤ד הַבַּהֶ֙רֶת֙ לֹ֣א פָשָׂ֔תָה צָרֶ֥בֶת הַשְּׁחִ֖ין הִ֑וא וְטִהֲר֖וֹ הַכֹּהֵֽן׃ (ס)
But if the bright spot stay in its place, and be not spread, it is the scar of the boil; and the priest shall pronounce him clean.
Mishnah Negaim
A boil and a burn do not combine, nor do they spread from one to the other, nor do they spread from there to the skin of the flesh, nor does [a nega] on the skin of the flesh spread to them. If they were festering they are clean. If they formed a scale as thick as garlic peel, such is the scar of the boil that is spoken of in the Torah. If they were subsequently healed, even though there was a mark in their place, they are regarded as the skin of the flesh.