There is a tree amongst trees, the leaves of which do not wither and that is like a Muslim; tell me which that (tree) can be? The people began to think of the trees of the forest. Abdullah said: I thought that it could be the date-palm tree, but I felt hesitant (to say that). They (the Companions) then said: Messenger of Allah, (kindly) tell us which that can be? Thereupon he said: It is the date-palm tree. I made a mention of that to 'Umar, whereupon he said: Had you said that it meant the date-palin tree, this statement of yours (would have been dearer to me) than such and such things. (Using translation from Muslim 2811a)
قَالَ رَسُولُ اللهِ ﷺ إِنَّ مِنَ الشَّجَرِ شَجَرَةً لَا يَسْقُطُ وَرَقُهَا وَإِنَّهَا مَثَلُ الرَّجُلِ الْمُسْلِمِ قَالَ فَوَقَعَ النَّاسُفِي شَجَرِ الْبَوَادِي وَكُنْتُ مِنْ أَحْدَثِ النَّاسِ وَوَقَعَ فِي صَدْرِي أَنَّهَا النَّخْلَةُ فَقَالَ رَسُولُ اللهِ ﷺ هِيَ النَّخْلَةُ قَالَ فَذَكَرْتُ ذَلِكَ لِأَبِي فَقَالَ لَأَنْ تَكُونَ قُلْتَهُ أَحَبُّ إِلَيَّ مِنْ كَذَا وَكَذَا