Surah 67. Al-Mulk, Ayah 9

Lit., "You are in nothing but a great error (dalal)" - thus denying the reality of divine revelation as such.

Allah's Signs were not only rejected or defied, but their very existence was denied. Nay, more, even their possibility was denied, and alas! righteous people and Prophets were persecuted or mocked (xxxvi. 30). They were called fools or madmen, or men under a delusion!