I said to Hasan bin Ali, "What did you memorize from the Messenger of Allah ﷺ?"He replied, "I memorized from the Messenger of Allah ﷺ, 'Leave what makes you doubt for what does not make you doubt, for truthfulness is tranquility and falsehood is doubt.'"The hadith contains a story.He said, Abu Hawra Saadi's name is Rabia bin Shayban.He said, this is a hasan sahih hadith.Bundar narrated to us, Muhammad bin Jafar narrated to us, Shuba narrated to us from Burayd, and he mentioned something similar.
حدثنا أبو موسى الأنصاري حدثنا عبد الله بن إدريس حدثنا شعبة عن بريد بن أبي مريم
قلت للحسن بن علي ما حفظت من رسول الله ﷺ قال حفظت من رسول الله ﷺ دع ما يريبك إلى ما لا يريبك فإن الصدق طمأنينة وإن الكذب ريبة وفي الحديث قصة قال وأبو الحوراء السعدي اسمه ربيعة بن شيبان قال وهذا حديث حسن صحيح حدثنا بندار حدثنا محمد بن جعفر حدثنا شعبة عن بريد فذكر نحوه
Its isnad is sahih. Nasai also narrated it, 8/327, 328, no. 5714, in the chapter on Ashribah, the section urging avoidance of doubtful matters, from the hadith of Ibn Idris, with the same wording. Ibn Khuzayma graded it sahih, no. 2348, as did Ibn Hibban, no. 512, and Hakim, 2/13, and Dhahabi agreed with him.