What is the hadith narrated by Abu Huraira which states what the Bani Israel were instructed to do upon entering a town according to the Prophet Muhammad (saw)?
 Narrated Abu Huraira:                     Allah's Apostle said, "It was said to Bani Israel, Enter the gate (of the town) with humility (prostrating yourselves) and saying: "Repentance", but they changed the word and entered the town crawling on their buttocks and saying: "A wheat grain in the hair."