Abdullah bin Umar (may Allah be pleased with him) narrates: The Prophet Muhammad (peace be upon him) said: "Indeed, among the trees there is a tree whose leaves do not fall, and its example is like that of a Muslim. Tell me, which tree is it?" The people began to think about the various trees of the forest. Abdullah (may Allah be pleased with him) says: It came to my mind that it is the date-palm tree, but I felt shy. Then the people said: O Messenger of Allah! Please tell us which tree it is. The Prophet Muhammad (peace be upon him) said: It is the date-palm tree. (The narrator says) Later, I mentioned this to Umar (may Allah be pleased with him), and he said: If you had said at that time that it is the date-palm tree, it would have been more beloved to me than such and such thing.
Hadith Referenceصحیح ابن حبان / كتاب الإيمان / 246
Hadith Gradingفضيلة الشيخ الإمام محمد ناصر الدين الألبانيصحيح - انظر ما قبله.فضيلة الشيخ العلّامة شُعيب الأرناؤوطإسناده صحيح على شرط مسلم.