كَلَّا ۖ إِنَّهُ كَانَ لِآيَاتِنَا عَنِيدًا
“But no! [For] he has been truly stubborn with Our revelations.”
This ayah is part of Surah al-Muddaththir's response to al-Walid ibn al-Mughira's private deliberations over how to denounce the Qur'an, described at this event -- classical tafsir identifies this passage (74:11-26) as addressing him directly.