Narrated Ibn 'Umar: The Prophet (P.B.U.H) said,
Amongst the trees, there is a tree, the leaves of which do not fall and is like a Moslem. Tell me the name of that tree"
Everybody started thinking about the trees of the desert areas and I thought of palm tree. The other then asked, "Pleae inform us which is that tree, O Allah's Apostle ?"
He replied, " It is the date palm-tree."
Sahih Al Bukhari
Volume: 1, Book: 3