Surah Al-Jathiyah, ayah 32

45:32

وَإِذَا قِيلَ إِنَّ وَعۡدَ ٱللَّهِ حَقّٞ وَٱلسَّاعَةُ لَا رَيۡبَ فِيهَا قُلۡتُم مَّا نَدۡرِي مَا ٱلسَّاعَةُ إِن نَّظُنُّ إِلَّا ظَنّٗا وَمَا نَحۡنُ بِمُسۡتَيۡقِنِينَ ٣٢

Wa idhā qīla inna wa'dallāhi haqqun was-sā'atu lā rayba fīhā qultum mā nadrī mas-sā'atu in nazunnu illā zannan wamā nahnu bimustayqinīn

And when it was said, 'Indeed, the promise of Allāh is truth and the Hour [is coming] - no doubt about it,' you said, 'We know not what is the Hour. We assume only assumption, and we are not convinced.'"