Sahih al-Bukhari 2708

It is related from 'Urwa ibn az-Zubayr that az-Zubayr quarrelled with a man of the Ansar who had been present at Badr about the irrigation canals of the lava-beds, and they took the case to the Prophet, may Allah bless him and grant him peace. Each of them used it for irrigation. The Messenger of Allah, may Allah bless him and grant him peace, said to az-Zubayr, "Zubayr, water, and then let the water pass to your neighbour." The Ansari became angry and said, "Messenger of Allah, is it because he is your aunt's son?" The face of the Messenger of Allah, may Allah bless him and grant him peace, changed colour and then he said, "Water and then hold the water until it reaches the wall." So at that time the Prophet, may Allah bless him and grant him peace, gave az-Zubayr his full right. Before that the Messenger of Allah, may Allah bless him and grant him peace, had suggested to az-Zubayr an opinion which was generous for him and for the Ansari. When the Ansari angered the Messenger of Allah, may Allah bless him and grant him peace, he gave az-Zubayr his full right according to the evident judgement. 'Urwa said that az-Zubayr said, "By Allah, indeed I think that this ayat was revealed about that, "No, by your Lord, they are not believers until they make you their judge in the disputes that break out between them."' (4:65)"