Musnad Ahmad 30:2129

Khalaf narrated to us, he said: Abbad ibn Abbad narrated to us, he said: Al-Hajjaj ibn Artah narrated to us, from Al-Tahawi, from Dhuhayl, from Abu Hurayrah, who said: We were on a journey with the Messenger of Allah, peace and blessings of Allah be upon him, and our provisions ran out and our supplies were depleted. We came upon camels whose udders were tied with tree bark, and the people rushed to them to milk them. The Messenger of Allah, peace and blessings of Allah be upon him, said to them: "These may contain the sustenance of a household of the Muslims. Would you like it if they came upon what is in your provisions and took it?" Then he said: "If you must do it, then drink, but do not carry [any away]."