The Prophet ﷺ used to take him and Hasan and say, "Allah, love them, for I love them."
عن النبي ﷺ أنه كان يأخذه والحسن، فيقول: اللهم أحبهما فإني أحبهما.
Bukhari narrated it in "The Virtues of the Companions of the Prophet" ﷺ (3735) from Musa bin Ismail, who said, Mutamir narrated to us, saying, I heard my father, Abu Uthman narrated to us, from Usama bin Zayd, and he related it.