Sayyiduna Abu Ayyub (may Allah be pleased with him) says: I went in to the Messenger of Allah (peace and blessings be upon him) while Hasan and Husayn (may Allah be pleased with them both) were playing in front of him and in his lap. I said: O Messenger of Allah! Do you love them? He (peace and blessings be upon him) said: "How could I not love them, when they are my two fragrant flowers of this world, whom I smell?"
Hadith Referenceالمعجم الكبير للطبراني / باب الخاء / 3975