Torah Temimah cites Toras Kohanim (Sifra, Vayikra Dibbura DeChovah, Chapter 13:1–2).
Sefaria — Toras Kohanim (Sifra, Vayikra Dibbura DeChovah, Chapter 13:1–2)
“Or a person who touches any unclean thing”… Scripture specifies “carcass of a wild animal… of a domestic animal… of a creeping thing” — just as these are unique in being primary sources of tumah, something that is not an av ha-tumah is excluded.
The named categories of neveilah are treated as avot ha-tumah. Contact with a mere toldah or with food/vessels that absorbed tumah does not trigger the oleh ve-yored of this verse.