TT #99 · Parshas Shemini · Aliyah 6 · Passuk 4
Chabad.org — Vayikra Chapter 11 with Rashi
English: “Those that chew the cud”: the verse includes an animal that has one sign but is born from an impure animal; it is nevertheless not permitted.
Bechoros 6a.
E-Daf.com — Bechoros 6a (Tsurras Hadaf)
מִמַּעֲלֵי הַגֵּרָה וְגוֹ׳. תָּנוּ רַבָּנַן, אַךְ אֶת זֶה לֹא תֹאכְלוּ מִמַּעֲלֵי הַגֵּרָה וּמִמַּפְרִיסֵי הַפַּרְסָה, יֵשׁ לְךָ שֶׁהוּא מַעֲלֶה גֵרָה וּמַפְרִיס פַּרְסָה וְאִי אַתָּה אוֹכֵל, וְאֵיזֶה זֶה, זֶה טָהוֹר הַנּוֹלָד מִן הַטָּמֵא.
Textual classification — The Chazal derives the teaching from the wording or classification in the verse.
An animal can display both kosher signs and still be forbidden when it is a pure-looking offspring born from a non-kosher animal; the prohibition follows its origin.