Surah Al-Jathiyah, Verse 32

وَإِذَا قِيلَ إِنَّ وَعۡدَ ٱللَّهِ حَقّٞ وَٱلسَّاعَةُ لَا رَيۡبَ فِيهَا قُلۡتُم مَّا نَدۡرِي مَا ٱلسَّاعَةُ إِن نَّظُنُّ إِلَّا ظَنّٗا وَمَا نَحۡنُ بِمُسۡتَيۡقِنِينَ٣٢

wa-idhā qīla inna waʿda l-lahi ḥaqqun wal-sāʿatu lā rayba fīhā qul'tum mā nadrī mā l-sāʿatu in naẓunnu illā ẓannan wamā naḥnu bimus'tayqinīna

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.'"