Sayyiduna Hudhayfah (may Allah be pleased with him) said: One day we saw signs of joy on the face of the Messenger of Allah (peace and blessings be upon him), so we said: O Messenger of Allah, we have seen the glad signs of joy on your face. He (peace and blessings be upon him) said: "How could I not be joyful, when Jibril (peace be upon him) came to me and gave me the glad tidings that Hasan and Husayn are the leaders of the youth of the people of Paradise, and that their father is better than them both?"
Hadith Referenceالمعجم الكبير للطبراني / باب الحاء / 2595