Musnad Ahmad 25:308

Muhammad ibn Ja‘far narrated to us, Shu‘bah narrated to us, from Habib—meaning Ibn al-Shahid—from ‘Abdullah ibn Abi Mulaykah, who said: I witnessed Ibn al-Zubayr and Ibn ‘Abbas. Ibn al-Zubayr said to Ibn ‘Abbas: "Do you remember when we met the Messenger of Allah, may Allah bless him and grant him peace, as he had come from a journey?" He said: "Yes. He carried me and so-and-so—a boy from the Banu Hashim—and left you."