Sahih Bukhari Volume 008, Book 073, Hadith Number 167.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 73. Good Manners and Form (Al-Adab)
Narated By Jundub : While the Prophet was walking, a stone hit his foot and stumbled and his toe was injured. He then (quoting a poetic verse) said, "You are not more than a toe which has been bathed in blood in Allah's Cause."