וְאִ֣ם ׀ יִרְאֶ֣נָּה הַכֹּהֵ֗ן וְהִנֵּ֤ה אֵֽין־בָּהּ֙ שֵׂעָ֣ר לָבָ֔ן וּשְׁפָלָ֥ה אֵינֶ֛נָּה מִן־הָע֖וֹר וְהִ֣יא כֵהָ֑ה וְהִסְגִּיר֥וֹ הַכֹּהֵ֖ן שִׁבְעַ֥ת יָמִֽים׃
But if the priest look on it, and, behold, there be no white hairs therein, and it be not lower than the skin, but be dim, then the priest shall shut him up seven days.
Read kabbalistic (mystical) interpretation of Leviticus 13:21: and classical mystical sources.