Sahih al-Bukhari 6144

Nafi' related from Ibn 'Umar that the Messenger of Allah, may Allah bless him and grant him peace, said, "Tell me about a tree which is like a Muslim. It gives its fruits in every season with the permission of its Lord and its leaves do not fall." He said, "It occurred to me that it was the palm tree, but I did not like to speak while Abu Bakr and 'Umar were there. When they did not speak, the Prophet, may Allah bless him and grant him peace, said, 'It is the palm tree.' When I left with my father, I said, 'Father, it occurred to me that it was the palm tree.' He said, 'What kept you from saying so? I would have preferred you saying that to such-and-such and such-and-such.' I said, "Nothing kept me except the fact that I did not see you or Abu Bakr speak and so I disliked to do so.'"