حَدَّثَنَا هِشَامُ بْنُ عَمَّارٍ، حَدَّثَنَا عَبْدُ الْعَزِيزِ بْنُ مُحَمَّدٍ الدَّرَاوَرْدِيُّ، حَدَّثَنَا يَزِيدُ بْنُ عَبْدِ اللَّهِ بْنِ الْهَادِ، عَنْ مُحَمَّدِ بْنِ إِبْرَاهِيمَ التَّيْمِيِّ، عَنْ بُسْرِ بْنِ سَعِيدٍ، عَنْ أَبِي قَيْسٍ، - مَوْلَى عَمْرِو بْنِ الْعَاصِ - عَنْ عَمْرِو بْنِ الْعَاصِ، أَنَّهُ سَمِعَ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ ‏"‏ إِذَا حَكَمَ الْحَاكِمُ فَاجْتَهَدَ فَأَصَابَ فَلَهُ أَجْرَانِ وَإِذَا حَكَمَ فَاجْتَهَدَ فَأَخْطَأَ فَلَهُ أَجْرٌ ‏"‏ ‏.‏ قَالَ يَزِيدُ فَحَدَّثْتُ بِهِ أَبَا بَكْرِ بْنَ عَمْرِو بْنِ حَزْمٍ، فَقَالَ هَكَذَا حَدَّثَنِيهِ أَبُو سَلَمَةَ، عَنْ أَبِي هُرَيْرَة‏.‏َ

It was narrated from 'Amr bin 'As that he heard the Messenger of Allah (PBUH) say: “When the judge passes a judgement and does his best and gets it right, he will have two rewards, and if he passes a judgement and does his best and gets it wrong, he will have one reward.” (Sahih) Yazid (one of narrators) said : “So I Narrated it to Abu Bakr bin 'Amr bin Hazm. He said: 'This is how it was narrated to me by Abu Salamah from Abu Hurairah.'” Translation Not Available

Book Ref: Sunan Ibn Majah Book 13 Hadith 2314
Web Ref:  Sunan Ibn Majah Vol 3 Book 13 Hadith 2314