Rashi on Deuteronomy 20:2/רש"י על דברים כ׳:ב׳

1כקרבכם אל המלחמה [IT SHALL BE] WHEN YE COME NIGH UNTO THE BATTLE, [THAT THE PRIEST … SHALL SPEAK] — i.e. when ye are on the point of leaving the ספר — the boundary of your land (Sifrei Devarim 191).

2ונגש הכהן AND “THE” PRIEST SHALL STEP NIGH [AND SPEAK] “the” priest means, he who has been anointed for that purpose; it is the one who is termed in the Talmud משוח מלחמה, “the priest anointed for war” (Sotah 42a).

3ודבר אל העם AND HE SHALL SPEAK UNTO THE PEOPLE — in the Holy Language (Sotah 42a).