Musnad Ahmad 25:1467

Yahya ibn Adam narrated to us, Israel narrated to us, from Abu Ishaq, from Muslim al-Batin, from Sa'id ibn Jubayr, from Ibn Abbas, who said: The Messenger of Allah (peace and blessings of Allah be upon him) used to recite in the dawn prayer on Friday: "Alif-Lam-Mim. The revelation of the Book..." (As-Sajdah) and "Has there not been over Man a period of time..." (Al-Insan).