Musnad Ahmad 32:370

Muhammad ibn Ja‘far narrated to us, Shu‘bah narrated to us, from Ya‘la ibn ‘Ata’, from Abu Fazara, who said: I asked Anas about the two rak‘ahs before the Maghrib prayer. He said: "We used to hasten to perform them during the time of the Messenger of Allah, may Allah bless him and grant him peace." Shu‘bah said: Then he said afterwards, and I asked him more than once, and he said: "We used to hasten to perform them," and he did not say: "during the time of the Messenger of Allah, may Allah bless him and grant him peace."