Abu Bakra reported,

The Messenger of Allah ﷺ was leading the people in prayer, and Hasan bin Ali would jump onto his back whenever he prostrated. He did this more than once.The people said to him, "By Allah, you do something with this child that we have never seen you do with anyone else."Mubarak said, He mentioned something, then said, "This son of mine is a master, and Allah will reconcile through him two great factions of the Muslims."Hasan said, By Allah, by Allah, after he assumed leadership, not so much as a cupping vessel's worth of blood was shed during his caliphate.

حدثنا هاشم حدثنا المبارك حدثنا الحسن حدثنا

أبو بكرة قال

كان رسول الله ﷺ يصلي بالناس وكان الحسن بن علي رضي الله عنهما يثب على ظهره إذا سجد ففعل ذلك غير مرة فقالوا له والله إنك لتفعل بهذا شيئا ما رأيناك تفعله بأحد قال المبارك فذكر شيئا ثم قال إن ابني هذا سيد وسيصلح الله تبارك وتعالى به بين فئتين من المسلمين فقال الحسن فوالله والله بعد أن ولي لم يهرق في خلافته ملء محجمة من دم