The Prophet ﷺ said, "Between the two blasts of the trumpet there are forty."The people asked, "Abu Hurayrah, forty days?"He replied, "I refuse to say."They asked, "Forty months?"He replied, "I refuse to say."They asked, "Forty years?"He replied, "I refuse to say.""Then Allah will send down water from the sky, and they will sprout just as vegetation sprouts. There is nothing of a human being that does not decay, except for one bone, which is the tailbone, and from it creation will be reassembled on the Day of Resurrection."
عن النبي ﷺ قال: بين النفختين أربعون قالوا: يا أبا هريرة، أربعون يوما؟ قال: أبيت، قالوا: أربعون شهرا؟ قال: أبيت، قالوا: أربعون سنة؟ قال: أبيت. ثم ينزل الله من السماء ماء فينبتون كما ينبت البقل قال: وليس من الإنسان شيء إلا يبلى، إلا عظما واحدا، وهو عجب الذنب، ومنه يركب الخلق يوم القيامة.
Bukhari related it in the tafsir (4935), and Muslim in asceticism and heart-softening narrations (2955), both through the route of Abu Muawiya, from Amash, from Abu Salih, from Abu Hurairah, who said, and he mentioned the hadith. The wording given is Muslim's, and Bukhari's wording is similar.A note, Bukhari related it from his teacher Muhammad without attributing him further, and he is Muhammad bin Salam bin Faraj Sulami, their client, Bikandi. As for Muslim, he related it from Abu Kurayb, Muhammad bin Ala bin Kurayb.