Hadithcore
Sunan Abi Dawud, 4624
sahih· Al-Albani

Ibn ‘Awn said:

If we learnt that the remark of al-Hasan would reach the extent that it has reached, we would write a book for his withdrawal and call witnesses to him; but we said: This is a remark that surprisingly came out (from him) and it will not be transmitted to others.

حَدَّثَنَا ابْنُ الْمُثَنَّى، وَابْنُ، بَشَّارٍ قَالاَ حَدَّثَنَا مُؤَمَّلُ بْنُ إِسْمَاعِيلَ، حَدَّثَنَا حَمَّادُ بْنُ زَيْدٍ، عَنِ ابْنِ عَوْنٍ، قَالَ لَوْ عَلِمْنَا أَنَّ كَلِمَةَ، الْحَسَنِ تَبْلُغُ مَا بَلَغَتْ لَكَتَبْنَا بِرُجُوعِهِ كِتَابًا وَأَشْهَدْنَا عَلَيْهِ شُهُودًا وَلَكِنَّا قُلْنَا كَلِمَةٌ خَرَجَتْ لاَ تُحْمَلُ ‏.‏

References2 variants
In-Book Reference
Book 42, Hadith 29
English Reference
Book 41, Hadith 4607