Sahih Bukhari Volume 1, Book 12, Hadith Number 735

Narated By Abu Rafi’ : Once I prayed the ‘Isha’ prayer with Abu Huraira and he recited, “Idha-s-Sama’ u-nShaqqat” (84) and prostrated. I said, “What is that?” He said, “I prostrated behind Abu-l-Qasim, (the Prophet) (when he recited that Sura) and I will go on doing it till I meet him.”