Sayyiduna Abu Bakrah (may Allah be pleased with him) narrates: The Prophet (peace and blessings be upon him) was praying, and Sayyiduna al-Hasan (may Allah be pleased with him) would come, and he was a little child. Whenever the Prophet (peace and blessings be upon him) prostrated, he would jump onto his neck and back, and the Prophet (peace and blessings be upon him) would raise his head gently until he set him down (on the ground). The Companions said: O Messenger of Allah, you treat this boy in a way we have never seen before. He (peace and blessings be upon him) said: "He is my sweet basil (rayhanah) in this world. This son of mine is a leader (sayyid), and it may be that Allah will bring about reconciliation through him between two groups of the Muslims."
Hadith Referenceالمعجم الكبير للطبراني / باب الحاء / 2578