Sahih Muslim
The Book Giving Description of the Day of Judgement, Paradise and Hell (Kitab Sifat Al-Qiyamah wal Janna wan-Nar)
Book Number: 039 / Hadith Number: 6751
Ibn Umar reported: We were'in the company of Allah's Messenger (may peace be upon him) that he said: Tell me of a tree which has resemblance to a Muslim and the leaves of which do not wither. Ibrahim said that perhaps Imam Muslim had stated like this: It constantly bears fruit but I have, however, seen [It does not bear fruit constantly]. Ibn Umar said: It crossed my mind that it could be the date-palm tree, but as I saw Aba Bakr and Umar observe silence, I did not deem it fit that I should speak or I should say something. 'Umar said: Had you said so, it would have been dearer to me than such and such thing.