Surah Al-Jathiyah (The Kneeling), Verse 32

وَاِذَا قِیْلَ اِنَّ وَعْدَ اللّٰهِ حَقٌّ وَّالسَّاعَةُ لَا رَیْبَ فِیْهَا قُلْتُمْ مَّا نَدْرِیْ مَا السَّاعَةُ اِنْ نَّظُنُّ اِلَّا ظَنًّا وَّمَا نَحْنُ بِمُسْتَیْقِنِیْنَ ۟

Wa izaa qeela inna wa'dallaahi haqqunw was Saa'atu laa raiba feehaa qultum maa nadree mas Saa'atu in nazunnu illaa zannanw wa maa nahnu bimustaiqineen

“"And when it was said that the promise of Allah was true, and that the Hour- there was no doubt about its (coming), ye used to say, 'We know not what is the hour: we only think it is an idea, and we have no firm assurance.'"”

Quran 45:32 (Yusuf Ali Translation)