Parashas Vaeira · Passuk 8:22
Chabad.org — English translation + Rashi
Torah Temimah points to Chullin 40a (verified).
Sefaria — Exodus 8:22
Sefaria — Chullin 40a
E-Daf — Chullin 40a
English: The Gemara discusses slaughter performed with mixed intentions, including slaughter for mountains, hills, rivers, deserts, celestial bodies, or an angelic power, and distinguishes those intentions from slaughter performed for a permitted purpose.
On the daf / in context: See the cited source for the full section.
Halakhic analysis of improper sacrificial intention
The verse’s concern about sacrificing what Egypt regards as sacred is connected by Chazal to the halakhic consequences of slaughter performed with an idolatrous or otherwise invalid intention.