Musannaf Ibn Abi Shayba 3:1554

Waki' narrated to us, from Habib ibn Abi Amra, from Abu Ja'far, who said: The Messenger of Allah (peace and blessings of Allah be upon him) would not abandon the two rak'ahs after the Maghrib and the two rak'ahs before the Fajr, neither in residence nor in travel.