Parashas Metzora · Passuk 14:40
Chabad.org — English translation + Rashi
Torah Temima points to Toras Kohanim.
English: “And they shall remove the stones” — one might think he may remove only two stones and thereby fulfill the mitzvah of removal; therefore the verse says “in which the nega is.” If it said only “in which the nega is,” one might think even axes or bricks [suffice]; therefore it says “stones.”
Definition of the removed material
Chazal require the actual stones that contain the nega to be removed; neither a token removal nor non-stone materials fulfill the requirement.