Musannaf Ibn Abi Shayba 27:558

Affan narrated to us, he said: Wuhayb narrated to us, from Abdullah ibn Uthman, from Sa’id ibn Abi Rashid, from Ya’la al-Amiri, that he went out with the Messenger of Allah (may Allah bless him and grant him peace) to a meal to which they were invited. He found Husayn playing with the boys in the road. He (the Prophet) went ahead of the people, then stretched out his hand, and the boy began to run here once and there once. The Messenger of Allah (may Allah bless him and grant him peace) began to make him laugh until the Messenger of Allah (may Allah bless him and grant him peace) caught him. He placed one of his hands under his chin and the other under the back of his head, then the Messenger of Allah (may Allah bless him and grant him peace) tilted his head up, placed his mouth upon his mouth, and kissed him. Then he said: "Husayn is from me and I am from Husayn. May Allah love whoever loves Husayn. Husayn is a grandson among the grandsons."