Musannaf Ibn Abi Shayba 27:665

Husayn ibn Ali narrated to us, from Za'idah, from Ma'mar, who said: Aisha said: "It is not appropriate for anyone to hate Usamah after what I heard from the Messenger of Allah, may Allah bless him and grant him peace, saying: 'Whoever loves Allah and His Messenger, let him love Usamah.'"