Jami` at-Tirmidhi 3641
جامع الترمذي#3641Sahihحَدَّثَنَا قُتَيْبَةُ، حَدَّثَنَا ابْنُ لَهِيعَةَ، عَنْ عُبَيْدِ اللَّهِ بْنِ الْمُغِيرَةِ، عَنْ عَبْدِ اللَّهِ بْنِ الْحَارِثِ بْنِ جَزْءٍ، قَالَ مَا رَأَيْتُ أَحَدًا أَكْثَرَ تَبَسُّمًا مِنْ رَسُولِ اللَّهِ صلى الله عليه وسلم . قَالَ أَبُو عِيسَى هَذَا حَدِيثٌ حَسَنٌ غَرِيبٌ .
Narrated Ibn Jaz:"I have not seen anyone who smiled more than the Messenger of Allah (ﷺ)
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
Ahmad Muhammad ShakirSahih
Al-AlbaniSahih
Zubair Ali ZaiDaif
In-book reference: 49:37