Musannaf Ibn Abi Shayba 3:4027

Waki’ narrated to us, he said: Al-Mas’udi narrated to us, from ‘Amr ibn Murrah, from Abu ‘Ubaydah, he said: It was difficult for ‘Abdullah to hear a speaker after the dawn—meaning after the two rak’ahs—except with the Qur’an or with the remembrance of Allah, until he prayed.