Musannaf Ibn Abi Shayba 3:4380

Abu Bakr ibn Ayyash narrated to us, from Abu Ishaq, from Alqama, who said: I prayed with Abdullah for an entire night. He would raise his voice, reciting in a recitation that the people of the mosque could hear. He would recite clearly and measuredly (tartil), and he would not repeat [the verses]. Then, when there remained before the dawn broke an amount of time equivalent to that between the Maghrib adhan and the completion of that prayer, he performed the Witr.