Musannaf Ibn Abi Shayba 27:667

'Abd al-Rahim ibn Sulayman narrated to us, from Hisham ibn 'Urwah, from his father, that the Messenger of Allah (may Allah bless him and grant him peace) dispatched an expedition before [Mu'tah] and appointed Usamah ibn Zayd as their commander. Among that expedition were Abu Bakr and 'Umar. He said: Some people criticized the Messenger of Allah (may Allah bless him and grant him peace) for appointing Usamah over them. So the Messenger of Allah (may Allah bless him and grant him peace) stood up and addressed the people, saying: "Some of you have criticized my appointment of Usamah, and they only criticized the appointment of Usamah just as they criticized the appointment of his father. By Allah, he was indeed worthy of command, and he was indeed among the most beloved of people to me. And his son is indeed among the most beloved of people to me after him. And I truly hope that he will be among your righteous ones, so treat him well."