Narrated Sa'd ibn AbuWaqqas:

The Prophet (ﷺ) said: I hope my community will not fail to maintain their position in the sight of their Lord if He delays them half a day. Sa'd was asked: How long is half a day? He said: It is five hundred years.

حَدَّثَنَا عَمْرُو بْنُ عُثْمَانَ، حَدَّثَنَا أَبُو الْمُغِيرَةِ، حَدَّثَنِي صَفْوَانُ، عَنْ شُرَيْحِ بْنِ عُبَيْدٍ، عَنْ سَعْدِ بْنِ أَبِي وَقَّاصٍ، أَنَّ النَّبِيَّ صلى الله عليه وسلم قَالَ ‏

‏ إِنِّي لأَرْجُو أَنْ لاَ تُعْجِزَ أُمَّتِي عِنْدَ رَبِّهَا أَنْ يُؤَخِّرَهُمْ نِصْفَ يَوْمٍ ‏

‏ ‏.‏ قِيلَ لِسَعْدٍ وَكَمْ نِصْفُ يَوْمٍ قَالَ خَمْسُمِائَةِ سَنَةٍ ‏.‏