Musannaf Ibn Abi Shayba 3:3580

Waki’ narrated to us, from Sufyan, from Abu Ishaq, from ‘Abd al-Rahman ibn Budayl, who said: It was narrated to me that the people used to look to ‘Abdullah ibn Mas’ud, for he would pray four rak’ahs in his house when the sun passed its zenith, making them long. And when the muezzins responded to one another, he would go out and sit in the mosque until the prayer was established.