Sahih Al Bukhari Hadith Number 766

Narrated Abu Rafi`: I offered the `Isha’ prayer behind Abu Huraira and he recited, “Idha s-samaa’u n-shaqqat” (84) and prostrated. On my inquiring, he said, “I prostrated behind Abul-Qasim (the Prophet) (when he recited that Sura) and I will go on doing it till I meet him.”

10  Call to Prayers (Adhaan)
Hadith number 766
Volume no 1
Chapter: 100 (To recite aloud in the ‘Isha’ prayer.)