Parashas Vayikra · Aliyah 2 · Passuk 15
Chabad.org — English translation + Rashi
Torah Temima points to Zevachim 65a (verified; hakohen — melikah with the kohen’s own nail).
English: “And the kohen shall bring it” — why state “the kohen”? So that the melikah shall be with the kohen’s own body [his nail].
Custom (specification of actor and instrument).
Melikah is done by a kohen using his fingernail, not with a knife.