Parashas Metzora · Passuk 15:05
Chabad.org — English translation + Rashi
Torah Temima points to Toras Kohanim.
English: “His bed” — equates his bed to him: just as he has purification in a mikveh, so his bed has purification in a mikveh.
Heqesh: purification parallel
Chazal require that the midras article itself be capable of mikveh purification (excluding earthenware, which has no mikveh remedy).