"They will not believe in it" (Al-Shu'ara: 201), meaning: in the Qur'an, "until they see the painful punishment," which means: the onset of the Hour.
﴿لَا يُؤمنُونَ بِهِ﴾ بِالْقُرْآنِ ﴿حَتَّى يَرَوُا الْعَذَابَ الأَلِيمَ﴾ يَعْنِي: قيام السَّاعَة