﴿ وَإِذَا قِيلَ إِنَّ وَعْدَ ٱللَّهِ حَقٌّۭ وَٱلسَّاعَةُ لَا رَيْبَ فِيهَا قُلْتُم مَّا نَدْرِى مَا ٱلسَّاعَةُ إِن نَّظُنُّ إِلَّا ظَنًّۭا وَمَا نَحْنُ بِمُسْتَيْقِنِينَ ﴾

“for when it was said, ‘Behold, God’s promise always comes true, and there can be no doubt about [the coming of] the Last Hour’ - you would answer, ‘We do not know what that Last Hour may be: we think it is no more than an empty guess, and [so] we are by no means convinced!’””

(And when it was said) to them in the life of the world: (Lo! Allah's promise) resurrection after death (is the Truth, and there is no doubt of the Hour's coming, ye said: We know not what the Hour is) we do not know what the coming of the Hour is. (We deem it naught but a conjecture) we only guess, (and we are by no means convinced) of the coming of the Hour.