Musnad Ahmad 81:1

Muhammad ibn Bakr narrated to us, Ubayd Allah ibn Abi Ziyad informed us, he said: Abd Allah ibn Kathir al-Dari narrated to me, from Mujahid, he said: A sheikh who lived through the Jahiliyyah narrated to us, while we were on the expedition of Rhodes, who was called Ibn Abs. He said: I was driving a cow for some of our kin. He said: Then I heard from its interior: "O family of Dharih, a clear speech," a man shouting: "There is no god but Allah." He said: So we arrived in Makkah, and we found that the Prophet, may Allah bless him and grant him peace, had already emerged.