TT #130 · Parshas Shemini · Aliyah 6 · Passuk 12
Chabad.org — Vayikra Chapter 11 with Rashi
English: Everything in the water that has no fins and scales shall be an abomination for you.
Sifra (Toras Kohanim), Shemini, Section 3.
Sefaria — Sifra, Shemini, Section 3
שֶׁקֶץ הוּא לָכֶם. שֶׁלֹּא יַעֲשֶׂה בּוֹ סְחוֹרָה.
Commercial restriction — The verse is read as prohibiting commercial trade in the forbidden creature.
The wording is used to restrict commercial dealing in the prohibited creatures.