Sahih Bukhari Volume 003, Book 049, Hadith Number 871.
Narated By Urwa bin Az-Zubair : Az-Zubair told me that he quarrelled with an Ansari man who had participated in (the battle of) Badr in front of Allah's Apostle about a water stream which both of them used for irrigation. Allah's Apostle said to Az-Zubair, "O Zubair! Irrigate (your garden) first, and then let the water flow to your neighbor." The Ansari became angry and said, "O Allah's Apostle! Is it because he is your cousin?" On that the complexion of Allah's Apostle changed (because of anger) and said (to Az-Zubair), "I irrigate (your garden) and then with-hold the water till it reaches the walls (surrounding the palms)." So, Allah's Apostle gave Az-Zubair his full right. Before that Allah's Apostle had given a generous judgment beneficial for Az-Zubair and the Ansari, but when the Ansan irritated Allah's Apostle he gave Az-Zubair his full right according to the evident law. Az-Zubair said, "By Allah ! I think the following Verse was revealed concerning that case: "But no by your Lord They can have No faith Until they make you judge In all disputes between them." (4.65)