Sahih Bukhari Volume 008, Book 073, Hadith Number 143.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 73. Good Manners and Form (Al-Adab)
Narated By Ibn 'Umar : The Prophet said, "The example of a believer is like a green tree, the leaves of which do not fall." The people said. "It is such-and-such tree: It is such-and-such tree." I intended to say that it was the date palm tree, but I was a young boy and felt shy (to answer). The Prophet said, "It is the date-palm tree." Ibn 'Umar added, " I told that to 'Umar who said, 'Had you said it, I would have preferred it to such-and such a thing."