Musannaf Ibn Abi Shayba 3:3997

'Abd al-A'la narrated to us, from Ibn Ishaq, who said: al-'Abbas ibn Sahl ibn Sa'd al-Sa'idi narrated to us, saying: "I reached the time of 'Uthman ibn 'Affan, and he would perform the taslim from the Maghrib prayer, and I would not see a single man praying them [the sunnah prayers] in the mosque. They would hasten to the doors of the mosque until they exited, and they would pray them in their houses."