Midrash su Levitico 13:50

7) (Vayikra 13:50) "And the Cohein shall see the plague-spot, and he shall quarantine the plague-spot for seven days.": This is the first quarantine.

8) If they (i.e., the essential words) have been stated in relation to the first week (Vayikra 13:5), why need they be restated in relation to the second week (Vayikra 13:6)? (i.e., let it simply be written "And the Cohein shall see it on the seventh day again and he shall declare him clean"?) — Because if a plague-spot in a garment remains unchanged the first week, it (the garment) is quarantined; and if it remains unchanged the second week, it is burned (see Vayikra 13:50-52). But if a plague-spot in a man remains unchanged the first week, he is quarantined; and if it remains unchanged the second week, he is declared tahor. (And if this were not clearly spelled out in 13:6, we would say that as a garment in those circumstances is burned at the end of the second week, so a man in those circumstances is to be declared tamei at the end of the second week. [And we would understand "And the Cohein shall declare him clean" as applying to an instance in which he was healed of the plague-spot]). It must, therefore, be spelled out in both the first week and the second week.