Musannaf Ibn Abi Shayba 36:457

Ubayd Allah ibn Musa narrated to us, from Musa ibn Ubaydah, who said: Umar, the freed slave of Amrah, informed me, saying: The Prophet, may Allah bless him and grant him peace, dismounted from a mule he was riding. He began calling out to the people: "O people of Surah al-Baqarah! O people of the Pledge of the Tree! I am the Messenger of Allah and His Prophet." So they turned away, retreating.