Musannaf Ibn Abi Shayba 3:3294

Abu Bakr narrated to us, he said: Ibn ‘Uyaynah narrated to us, he said: Ayyub narrated to us, he said: I heard ‘Ata’ from Ibn ‘Abbas saying: I bear witness regarding the Messenger of Allah, may Allah bless him and grant him peace, that he would pray before the sermon, then he would deliver the sermon.