Musnad Ahmad 1239:6

'Abd al-Razzaq narrated to us, he said: Ma'mar narrated to us, from Ibn Tawus, from 'Ikrimah ibn Khalid, from al-Muttalib ibn Abi Wada'ah, who said: "I saw the Messenger of Allah, peace and blessings of Allah be upon him, prostrate in [Surah] al-Najm, and the people prostrated with him." Al-Muttalib said: "And I did not prostrate with them—and he was a polytheist on that day." Al-Muttalib said: "And I will never abandon the prostration in it ever."