From Sahih Muslim (Hadith 1304):
Abu Rafi' reported:I said the night prayer along with Abu Huraira and -as he recited:" When the heaven burst asunder," he performed prostration. Isaid to him: What prostration is this? He said: I prostrated myself (on this occasion of recital) behind Abu'I-Qasim (Muhammad. may peace be upon him), and Iwould go on doing this till I meet him (in the next world). Ibn 'Abu al-A'la said: (Abu Huraira uttered this: ) I would not abandon performing prostration
Reference: Muslim 1304