Musnad Abu Ya'la al-Mawsili 109:105

Muhammad ibn al-Khattab narrated to us, Mu'ammal narrated to us, Sufyan narrated to us, 'Abdullah ibn Muhammad ibn 'Aqil narrated to us, he said: I heard Jabir ibn 'Abdullah saying: I used to pray the Maghrib with the Messenger of Allah (may Allah bless him and grant him peace), then I would return to my family in Banu Salama, and they were at a distance of a mile from Medina—or he said: from the mosque—and I could see the landing places of the arrows. Then he said: The Dhuhr is as its name implies, at midday (zuhra). The 'Asr is while the sun is white and pure. The Maghrib is as its name implies. As for the 'Isha, the Prophet (may Allah bless him and grant him peace) used to delay it sometimes and hasten it sometimes.