حَدَّثَنَا أَبُو كُرَيْبٍ، مُحَمَّدُ بْنُ الْعَلاَءِ حَدَّثَنَا أَبُو مُعَاوِيَةَ، عَنِ الأَعْمَشِ، عَنْ أَبِي صَالِحٍ، عَنْ أَبِي هُرَيْرَةَ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ مَا بَيْنَ النَّفْخَتَيْنِ أَرْبَعُونَ ‏"‏ ‏.‏ قَالُوا يَا أَبَا هُرَيْرَةَ أَرْبَعُونَ يَوْمًا قَالَ أَبَيْتُ ‏.‏ قَالُوا أَرْبَعُونَ شَهْرًا قَالَ أَبَيْتُ ‏.‏ قَالُوا أَرْبَعُونَ سَنَةً قَالَ أَبَيْتُ ‏"‏ ثُمَّ يُنْزِلُ اللَّهُ مِنَ السَّمَاءِ مَاءً فَيَنْبُتُونَ كَمَا يَنْبُتُ الْبَقْلُ ‏"‏ ‏.‏ قَالَ ‏"‏ وَلَيْسَ مِنَ الإِنْسَانِ شَىْءٌ إِلاَّ يَبْلَى إِلاَّ عَظْمًا وَاحِدًا وَهُوَ عَجْبُ الذَّنَبِ وَمِنْهُ يُرَكَّبُ الْخَلْقُ يَوْمَ الْقِيَامَةِ ‏"‏ ‏.‏
Translation
Abu Huraira reported Allah's Messenger (ﷺ) as saying

Between the two blowings of the trumpet (there would be an interval of forty). They said: Abu Huraira, do you mean forty days? He said: I cannot say anything. They said: Do you mean forty months? He said: I cannot say anything. They said: Do you mean forty years? He said: I cannot say anything. Then Allah would cause the water to, descend from the sky and they (people) will sprout like vegetable. The only thing in a man which would not decay would be one bone (the tailbone) from which the whole frame would be reconstituted on the Day of Resurrection.