Musannaf Ibn Abi Shayba 3:6001

Waki’ narrated to us, from Jarir, from al-Sha’bi, and from Sufyan, from Jabir, from Mujahid, and from Abu al-Miqdam, from Mu’awiyah ibn Qurrah, from Abdullah ibn Mughaffal, regarding the saying of the Exalted: "And when the Qur’an is recited, then listen to it and pay attention." They said: In the prayer.