The people of the pre-Islamic era used to eat certain things and avoid others out of disgust. Then Allah the Exalted sent His Prophet, revealed His Book, declared lawful what is lawful, and forbade what is forbidden. So whatever He made lawful is lawful, whatever He forbade is forbidden, and whatever He remained silent about is pardoned.Then he recited, "Say, I do not find within that which was revealed to me anything forbidden" [Anam 6:145], to the end of the verse.
كان أهل الجاهلية يأكلون أشياء، ويتركون أشياء تقذرا، فبعث الله تعالى نبيه، وأنزل كتابه، وأحل حلاله وحرم حرامه، فما أحل فهو حلال، وما حرم فهو حرام، وما سكت عنه فهو عفو وتلا: {قل لا أجد في ما أوحي إلى محرما} إلى آخر الآية.
Reported by Abu Dawud (3800), Ibn Abu Hatim in his Tafsir (8000), and Hakim (4/115), all of them via Abu Naeem Fadl bin Dukayn, who said, Muhammad bin Sharik Makki narrated to us, from Amr bin Dinar, from Abu Shatha, from Ibn Abbas, and he related it. Its isnad is sahih. Abu Shatha is Jabir bin Zayd Basri, well known by his kunyah. Hakim also declared its isnad sahih.I say, on its face it appears mawquf, but it contains an account concerning the overall mission of the Prophet ﷺ regarding what is lawful and what is forbidden.