Sayyiduna Abu Bakrah (may Allah be pleased with him) narrates: The Messenger of Allah (peace and blessings be upon him) prayed one day, and with him were Sayyiduna al-Hasan and Sayyiduna al-Husayn (may Allah be pleased with them both). When he (peace and blessings be upon him) prostrated, Sayyiduna al-Hasan came and jumped onto his back, and whenever he raised his head he would (carefully) tilt him to one side, out of concern that he might fall. When he finished the prayer, he took him by the hand, sat him in his lap and kissed him, and said: "This son of mine is a leader (sayyid), and he is my sweet basil (rayhanah) in this world, and I hope that Allah will bring about reconciliation through him between two great groups of the Muslims."
Hadith Referenceالمعجم الكبير للطبراني / باب الحاء / 2581