Musannaf Ibn Abi Shayba 27:544

Khalid ibn Makhlad narrated to us, he said: Musa ibn Ya'qub al-Zam'i narrated to us, from Abdullah ibn Abi Bakr ibn Zayd ibn al-Muhajir, he said: Muslim ibn Abi Sahl al-Nibal informed me, he said: Hasan ibn Usama ibn Zayd informed me, he said: My father, Usama, informed me, saying: I knocked on the door of the Messenger of Allah, may Allah bless him and grant him peace, one night for some need. He came out to me while he was wrapped in something, I do not know what it was. When I finished my need, I said: "What is this that you are wrapped in?" He uncovered it, and behold, it was Hasan and Husayn on his hips. He said: "These are my sons and the sons of my daughter. O Allah, You know that I love them, so love them."