Rashi on Leviticus 13:35/רש"י על ויקרא י״ג:ל״ה

1אחרי טהרתו [AND IF THE SCALL SPREADS AT ALL …] AFTER HIS BEING PRONOUNCED CLEAN — I have here only the statement that he is unclean if it spreads after he has been freed from the quarantine; whence do I know that the same applies if it has spread by the end of the first week and or by the end of the second week? Because it states here: “if it spreads at all” (Sifra, Tazria Parashat Nega'im, Chapter 9 9).