Musannaf Ibn Abi Shayba 33:961

Zayd ibn al-Hubab narrated to us, he said: Uqbah ibn Abi Yazid al-Qurashi narrated to me, he said: I heard Zayd ibn Aslam mentioning regarding the saying of Allah, "And those who seek forgiveness before dawn": He said, "Whoever attends the morning prayer."