Musnad Ahmad 28:149

Ishaq narrated to us, Layth ibn Sa’d narrated to me, Haywah ibn Shurayh narrated to me, from Ibn Shafi al-Asbahi, from his father, from Abdullah ibn Amr, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "A return from a military expedition is like a military expedition."