Extra Credit · Parallel Chazal
English: But if the netek spreads in the skin after his purification,
Chabad.org — Rashi for Vayikra 13:35
Toras Kohanim (Sifra), Tazria, Parashas Nega'im 9 (cited by Rashi on Vayikra 13:35)
Sefaria — Sifra, Tazria, Parashat Nega'im 9:11
English: I know only that spreading after the person has been released from quarantine makes the condition impure. How do I know the same applies if it spreads at the end of the first week or the second week? Scripture says, “it spreads indeed.”
The infinitive absolute followed by the finite verb—פָּשֹׂה יִפְשֶׂה—extends the rule beyond spreading after release: spreading at either weekly examination also counts.