Abu Rawahah Yazid bin Ayham said: Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) wrote to the people: Keep all people equal in (matters of) truth; their near one is like the distant one, and the distant one like the near one. Beware of bribery, beware of judging according to desires, and leave people alone at the time of anger. Establish the truth, even if it be for a single hour of the day.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب آداب القاضي / 20462