Yahya related to me from Malik from Yahya ibn Said from Muhammadibn Ibrahim ibn alHarith at-Taymi from Yahya ibn Abd ar-Rahman ibnHatib that Umar ibn al-Khattab set out on one occasion with a party ofriders, one of whom was Amr ibn al-As. They came to a watering placeand Amr ibn al-As asked the man who owned it whether wild beasts drankfrom it. Umar ibn al-Khattab told the owner of the watering place notto answer, since the people drank after the wild beasts and the wildbeasts drank after them.
USC-MSA web (English) reference: Book 2, Hadith 14
Arabic reference: Book 2, Hadith 44