What was the reason behind Abu Huraira's prostrations when he offered prayer behind the Prophet Muhammad (saw)?
 Narrated Abu Rafi`:                     I offered the `Isha' prayer behind Abu Huraira and he recited Idhas-Sama' Un-Shaqqat, and prostrated. I said, "What is this?" Abu Huraira said, "I prostrated behind Abul-Qasim and I will do the same till I meet him."