Sahih Bukhari
Prophets
Volume: 004 / Book Number: 055 / Hadith Number: 615
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."