Good Manners and Form (Al-Adab)
Bukhari :: Book 8 :: Volume 73 :: Hadith 143
Narrated 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 datepalm 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."