Sunan Abi Dawud 4623
سنن أبي داود#4623Sahihحَدَّثَنَا ابْنُ الْمُثَنَّى، أَنَّ يَحْيَى بْنَ كَثِيرٍ الْعَنْبَرِيَّ، حَدَّثَهُمْ قَالَ كَانَ قُرَّةُ بْنُ خَالِدٍ يَقُولُ لَنَا يَا فِتْيَانُ لاَ تُغْلَبُوا عَلَى الْحَسَنِ فَإِنَّهُ كَانَ رَأْيُهُ السُّنَّةَ وَالصَّوَابَ .
Yahya b. Kathir al-‘Anbari said:Qurrah b. Khalid used to tell us: O young people! Do not think that al-Hasan denied predestination, for his opinion (i.e., belief) was sunnah and sight
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:
Al-AlbaniSahih
Muhammad Muhyi Al-Din Abdul HamidSahih Lighairihi
Shuaib Al ArnautSahih
Zubair Ali ZaiIsnaad Sahih
In-book reference: 42:28