TT #245 · Parshas Shemini · Aliyah 7 · Passuk 42
Chabad.org — Vayikra Chapter 11 with Rashi
English: “Belly”: the letter vav in the word גחון is the subject of a traditional textual observation.
Kiddushin 30a.
E-Daf.com — Kiddushin 30a (Tsurras Hadaf)
Textual observation — The Chazal applies the verse’s wording and structure to establish the stated teaching.
The enlarged vav is noted as the Torah's traditional letter midpoint.