Parashas Metzora · Passuk 14:02
Chabad.org — English translation + Rashi
Torah Temima points to Menachos 5a (verified on the daf).
E-Daf.com — Tsurras Hadaf (size=3)
HebrewBooks / Shas PDF of the daf
English: “This shall be” — it shall be in its [prescribed] form.
Gezeiras ha-kasuv (precise wording of “tihyeh”)
Chazal teach that the purification procedure of the metzora must be performed in the exact order set forth in the Torah; the word “tihyeh” locks the sequence in place. If the order is altered, the offering is invalid unless the earlier element can still be supplied later.