Quran 6:147 — Livestock (Al-An'am)

If they disbelieve you, then say, "Your Lord possesses infinite mercy, but His retribution is unavoidable for the guilty people."

[6:146] For those who are Jewish we prohibited animals with undivided hoofs; and of the cattle and sheep we prohibited the fat, except that which is carried on their backs, or in the viscera, or mixed with bones. That was a retribution for their transgressions, and we are truthful.

[6:148] The idol worshipers say, "Had GOD willed, we would not practice idolatry, nor would our parents, nor would we prohibit anything." Thus did those before them disbelieve, until they incurred our retribution. Say, "Do you have any proven knowledge that you can show us? You follow nothing but conjecture; you only guess."