TT #96 · Parshas Shemini · Aliyah 6 · Passuk 4
Chabad.org — Vayikra Chapter 11 with Rashi
English: “Only this you shall not eat”: this one you may not eat, but an animal born from a pure animal and itself having one identifying sign may be eaten.
Bechoros 7a.
E-Daf.com — Bechoros 7a (Tsurras Hadaf)
אַךְ אֶת זֶה. זֶה אִי אַתָּה אוֹכֵל, אֲבָל אַתָּה אוֹכֵל הַבָּא בְּסִימָן אֶחָד, וְאֵיזֶה הוּא? זֶה טָמֵא הַנּוֹלָד מִן הַטָּהוֹר וְעִבּוּרוֹ מִן הַטָּהוֹר.
Textual inclusion — The Chazal derives the teaching from the wording or classification in the verse.
The limiting word אך excludes the animal with both visible kosher signs from the general prohibition only when its status is that of a tame offspring born from a pure animal; the note identifies the relevant exceptional case.