The Mishnah on the Purity of Skin Afflictions of Non-Jews
m. Nega‘im 3:1
All can be rendered ritually impure by skin afflictions, except for a gentile and a resident alien.
m. Nega‘im 7:1
The following bright skin spots are ritually pure: those that existed before the Torah was given and those of a gentile at the time of conversion.
Translated by Christine Hayes.
Published in: The Posen Library of Jewish Culture and Civilization, vol. 2: Emerging Judaism.