Good Manners and Form (Al-Adab)
Ṣaḥīḥ al-Bukhārī 6122
مَثَلُ الْمُؤْمِنِ كَمَثَلِ شَجَرَةٍ خَضْرَاءَ، لاَ يَسْقُطُ وَرَقُهَا، وَلاَ يَتَحَاتُّ
mathalu al-muʾmini kamathali shajaratin khaḍrāʾa, lā yasquṭu waraquhā, walā yataḥāttu
Transliteration generated from the Arabic vowel marks
The full narration
Narrated Ibn `Umar:The Prophet (ﷺ) said, "The example of a believer is like a green tree, the leaves of which do not fall." The people said. "It is such-and-such tree: It is such-and-such tree." I intended to say that it was the datepalm tree, but I was a young boy and felt shy (to answer). The Prophet (ﷺ) said, "It is the date-palm tree." Ibn `Umar added, " I told that to `Umar who said, 'Had you said it, I would have preferred it to such-and such a thing
Source
Ṣaḥīḥ al-Bukhārī · 6122
Ṣaḥīḥ