TT #215 · Parshas Shemini · Aliyah 7 · Passuk 36
Chabad.org — Vayikra Chapter 11 with Rashi
English: “A mikveh of water”: the wording limits the required substance to water and excludes other liquids.
Chullin 84a.
E-Daf.com — Chullin 84a (Tsurras Hadaf)
Textual limitation — The Chazal derives the stated rule from the wording and structure of the verse.
מקוה מים restricts the category to water.