Musnad Ahmad 25:170

Yahya narrated to us, from Sufyan, Sulayman—meaning al-A’mash—narrated to me, from Yahya ibn ‘Umarah, from Sa’id ibn Jubayr, from Ibn ‘Abbas, who said: Abu Talib became ill, so the Quraysh came to him, and the Messenger of Allah (peace and blessings of Allah be upon him) came to visit him. At his head was the space for a man to sit, so Abu Jahl stood up and sat in it. They said: "Your nephew insults our gods." He (Abu Talib) said: "What is the matter with your people that they complain about you?" He (the Prophet) said: "O my uncle, I want them to agree upon a single word through which the Arabs will submit to them and the non-Arabs will pay them tribute." He said: "What is it?" He said: "There is no god but Allah." They stood up and said: "Does he make the gods one god?" He said: Then it was revealed: "Sad. By the Qur'an, full of reminder" [Sad: 1]. He recited until he reached: "Indeed, this is a strange thing" [Sad: 5]. Abu Usamah narrated to us, al-A’mash narrated to us, ‘Abbad narrated to us, and he mentioned the like of it. My father said: Al-Ashja’i said: Yahya ibn ‘Abbad.