Musnad Ahmad 33:632

Musa narrated to us, Ibn Lahi'ah narrated to us, from Abu al-Zubayr, that he said: I asked Jabir, "Did the Messenger of Allah, peace and blessings of Allah be upon him, combine the Maghrib and Isha prayers?" He said: "Yes, at the time we raided Banu al-Mustaliq."