Musnad Ahmad 32:174

Isma'il narrated to us, Ayyub narrated to us, from Humayd ibn Hilal, from Anas ibn Malik, who said: The Messenger of Allah (peace and blessings of Allah be upon him) delivered a sermon and said: "Zayd took the banner and was struck down. Then Ja'far took it and was struck down. Then 'Abdullah ibn Rawahah took it and was struck down"—and his eyes were shedding tears—"then Khalid took it without being appointed, and Allah granted him victory. And it would not please me that they were with us," or he said: "It would not please them that they were with us."