וְרָאָ֥הוּ הַכֹּהֵ֖ן בַּיּ֣וֹם הַשְּׁבִיעִ֑י אִם־פָּשֹׂ֤ה תִפְשֶׂה֙ בָּע֔וֹר וְטִמֵּ֤א הַכֹּהֵן֙ אֹת֔וֹ נֶ֥גַע צָרַ֖עַת הִֽוא׃
And the priest shall look upon him the seventh day; if it spread abroad in the skin, then the priest shall pronounce him unclean: it is the plague of leprosy.
Read halakhic rulings (Jewish law) on Leviticus 13:27: and classical halakhic sources.