Hadithcore
Mishkat al-Masabih, 3740

‘A’isha reported God's Messenger as saying, “The day of resurrection will come to the just <i>qadi</i> and he will wish he had never given judgment between two men about a single date.”* Ahmad transmitted it. * He will wish he had never given judgment even about the most insignificant matters.

وَعَنْ عَائِشَةَ عَنْ رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ: «لَيَأْتِيَنَّ عَلَى الْقَاضِي الْعَدْلِ يومُ القيامةِ يَتَمَنَّى أَنَّهُ لَمْ يَقْضِ بَيْنَ اثْنَيْنِ فِي تَمْرَة قطّ» . رَوَاهُ أَحْمد

References1 variant
In-Book Reference
Book 18, Hadith 79