Sayyiduna Ibn Abbas (may Allah be pleased with them both) said: Abu Sufyan bin Harb came to the Prophet (peace and blessings be upon him) and said: O Muhammad, I adjure you by Allah and by the ties of kinship; we have eaten 'ilhiz - that is, camel hair mixed with blood. So Allah, the Mighty and Majestic, revealed this verse: "And We certainly seized them with punishment, yet they did not humble themselves before their Lord, nor do they implore (Him)." [Surah al-Mu'minun: 76]
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 11986