Narrated Abu Sa`id Al-Khudri:

Allah's Messenger (ﷺ) said, "On the Day of Resurrection Death will be brought forward in the shape of a black and white ram. Then a call maker will call, 'O people of Paradise!' Thereupon they will stretch their necks and look carefully. The caller will say, 'Do you know this?' They will say, 'Yes, this is Death.' By then all of them will have seen it. Then it will be announced again, 'O people of Hell !' They will stretch their necks and look carefully. The caller will say, 'Do you know this?' They will say, 'Yes, this is Death.' And by then all of them will have seen it. Then it (that ram) will be slaughtered and the caller will say, 'O people of Paradise! Eternity for you and no death O people of Hell! Eternity for you and no death."' Then the Prophet, recited:-- 'And warn them of the Day of distress when the case has been decided, while (now) they are in a state of carelessness (i.e. the people of the world) and they do not believe.' (19.39)

حَدَّثَنَا عُمَرُ بْنُ حَفْصِ بْنِ غِيَاثٍ، حَدَّثَنَا أَبِي، حَدَّثَنَا الأَعْمَشُ، حَدَّثَنَا أَبُو صَالِحٍ، عَنْ أَبِي سَعِيدٍ الْخُدْرِيِّ ـ رضى الله عنه ـ قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ يُؤْتَى بِالْمَوْتِ كَهَيْئَةِ كَبْشٍ أَمْلَحَ فَيُنَادِي مُنَادٍ يَا أَهْلَ الْجَنَّةِ، فَيَشْرَئِبُّونَ وَيَنْظُرُونَ فَيَقُولُ هَلْ تَعْرِفُونَ هَذَا فَيَقُولُونَ نَعَمْ هَذَا الْمَوْتُ، وَكُلُّهُمْ قَدْ رَآهُ، ثُمَّ يُنَادِي يَا أَهْلَ النَّارِ، فَيَشْرَئِبُّونَ وَيَنْظُرُونَ، فَيَقُولُ هَلْ تَعْرِفُونَ هَذَا فَيَقُولُونَ نَعَمْ هَذَا الْمَوْتُ، وَكُلُّهُمْ قَدْ رَآهُ، فَيُذْبَحُ ثُمَّ يَقُولُ يَا أَهْلَ الْجَنَّةِ، خُلُودٌ فَلاَ مَوْتَ، وَيَا أَهْلَ النَّارِ، خُلُودٌ فَلاَ مَوْتَ ثُمَّ قَرَأَ ‏{‏وَأَنْذِرْهُمْ يَوْمَ الْحَسْرَةِ إِذْ قُضِيَ الأَمْرُ وَهُمْ فِي غَفْلَةٍ‏}‏ وَهَؤُلاَءِ فِي غَفْلَةٍ أَهْلُ الدُّنْيَا ‏{‏وَهُمْ لاَ يُؤْمِنُونَ‏}‏‏"‏
USC-MSA web (English) reference : Vol. 6, Book 60, Hadith 254
Arabic reference : Book 65, Hadith 4730