1)
What is the point of washing the garment again?
1.
Rashi (citing Targum Onkelos) and Targum Yonasan: Even though every other Lashon 'Kibus' in the Parshah means 'washing', here it means 'Toveling in a Mikvah'. 1
1
See also Torah Temimah, note 245.
2)
Since when is leather -which is hard, subject to Kibus?
1.
Zevachim. 94a: The Nega that comes from within the article causes it to become soft. 1
1
See Oznayim la'Torah, who elaborates. See also Torah Temimah, citing Zevachim, 94a.
3)
Why does the Torah add the (otherwise superfluous) word "Vesar meihem ha'Naga"?
1.
Sifra: To teach us that every trace of the Nega must be removed.