The Quran

138

وَقالوا هٰذِهِ أَنعامٌ وَحَرثٌ حِجرٌ لا يَطعَمُها إِلّا مَن نَشاءُ بِزَعمِهِم وَأَنعامٌ حُرِّمَت ظُهورُها وَأَنعامٌ لا يَذكُرونَ اسمَ اللَّهِ عَلَيهَا افتِراءً عَلَيهِ ۚ سَيَجزيهِم بِما كانوا يَفتَرونَ

(Saheeh International)

And they say, "These animals¹ and crops are forbidden; no one may eat from them except whom we will," by their claim. And there are those [camels] whose backs are forbidden [by them]² and those upon which the name of Allāh is not mentioned³ – [all of this] an invention of untruth about Him.⁴ He will punish them for what they were inventing.

The four categories of grazing livestock called "an‘ām" collectively.
See 5:103.
At the time of slaughter. Rather, they are dedicated to others among their "deities."
i.e., false assertions that such practices are part of Allāh's religion.