Musnad Abu Ya'la al-Mawsili 154:188

Abu Sa'id 'Ubayd Allah ibn 'Umar al-Qawariri narrated to us, Abu Umayyah ibn Ya'la al-Thaqafi narrated to us, he said: Nafi', the freed slave of 'Abd Allah ibn 'Umar, informed me, from 'Abd Allah ibn 'Umar, he said: I witnessed the Messenger of Allah, may Allah bless him and grant him peace, praying the two rak'ahs after the Maghrib in his house, and the two rak'ahs after the 'Isha prayer in his house.