ENOfficial
Abu Bakra told that he heard God’s Messenger say, “No judge must give judgment between two people when he is angry.” (Bukhari and Muslim.)
Source: sunnah.com
Other translations
Arabic
عَنْ أَبِي بَكْرَةَ قَالَ سَمِعْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَقُولُ: «لَا يَقْضِيَنَّ حَكَمٌ بَيْنَ اثْنَيْنِ وَهُوَ غَضْبَانُ»
sunnah.com