Al-Sha’bi reported: Ali ibn Abi Talib saw a Christian man wearing his lost armor and he decided to take up the matter legally, so he brought the dispute to the judge Shurayh. Ali said, “This is my armor and I have not sold it or given it away.” The judge said to the Christian, “What do you say about what the commander of the faithful has said?” The Christian said, “It is my armor, but I do not consider the commander of the faithful to be a liar.” The judge turned to Ali and he said, “O commander of the faithful, do you have proof?” Ali laughed and he said, “Shurayh is correct. I do not have proof.” Thus, the judge ruled in favor of the Christian. The Christian took the armor and began to walk away, but then he returned and he said, “As for me, I testify that this is the wisdom of the prophets. The commander of the faithful himself has taken me to his judge and the judge has ruled against him! I testify that there is no God but Allah and Muhammad is the Messenger of Allah. By Allah, the armor is yours. I followed the army while you were on your way to Siffin and the armor fell from your luggage.” Ali said, “If you have embraced Islam, the armor is yours.”
Source: al-Bdāyah wal-Nihāyah 11/107
عَنِ الشَّعْبِيِّ قَالَ وَجَدَ عَلِيُّ بْنُ أَبِي طَالِبٍ دِرْعَهُ عِنْدَ رَجُلٍ نَصْرَانِيٍّ فَأَقْبَلَ بِهِ إِلَى شُرَيْحٍ يُخَاصِمُهُ قَالَ فَجَاءَ عَلِيٌّ حَتَّى جَلَسَ إِلَى جَنْبِ شُرَيْحٍ وَقَالَ يَا شُرَيْحُ لَوْ كَانَ خَصْمِي مُسْلِمًا مَا جَلَسْتُ إِلَّا مَعَهُ وَلَكِنَّهُ نَصْرَانِيٌّ وَقَدْ قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ إِذَا كُنْتُمْ وَإِيَّاهُمْ فِي طَرِيقٍ فَاضْطَرُّوهُمْ إِلَى مَضَايِقِهِ وَصَغِّرُوا بِهِمْ كَمَا صَغَّرَ اللَّهُ بِهِمْ مِنْ غَيْرِ أَنْ تَطْغَوْا ثُمَّ قَالَ هَذَا الدِّرْعُ دِرْعِي وَلَمْ أَبِعْ وَلَمْ أَهَبْ فَقَالَ شُرَيْحٌ لِلنَّصْرَانِيِّ مَا تَقَولُ فِيمَا يَقُولُ أَمِيرُ الْمُؤْمِنِينَ فَقَالَ النَّصْرَانِيُّ مَا الدِّرْعُ إِلَّا دِرْعِي وَمَا أَمِيرُ الْمُؤْمِنِينَ عِنْدِي بِكَاذِبٍ فَالْتَفَتَ شُرَيْحٌ إِلَى عَلِيٍّ فَقَالَ يَا أَمِيرَ الْمُؤْمِنِينَ هَلْ مِنْ بَيِّنَةٍ فَضَحِكَ عَلِيٌّ وَقَالَ أَصَابَ شُرَيْحٌ مَا لِي بَيِّنَةٌ فَقَضَى بِهَا شُرَيْحٌ لِلنَّصْرَانِيِّ قَالَ فَأَخْذُهَا النَّصْرَانِيُّ وَمَشَى خُطًى ثُمَّ رَجَعَ فَقَالَ أَمَّا أَنَا فَأَشْهَدُ أَنَّ هَذِهِ أَحْكَامُ الْأَنْبِيَاءِ أَمِيرُ الْمُؤْمِنِينَ قَدَّمَنِي إِلَى قَاضِيهِ وَقَاضِيهِ يَقْضِي عَلَيْهِ أَشْهَدُ أَنْ لَا إِلَهَ إِلَّا اللَّهُ وَأَشْهَدُ أَنَّ مُحَمَّدًا عَبْدُهُ وَرَسُولُهُ الدِّرْعُ وَاللَّهِ دِرْعُكَ يَا أَمِيرَ الْمُؤْمِنِينَ اتَّبَعْتُ الْجَيْشَ وَأَنْتَ مُنْطَلِقٌ إِلَى صِفِّينَ فَخَرَجَتْ مِنْ بَعِيرِكَ الْأَوْرَقِ فَقَالَ أَمَا إِذْ أَسْلَمْتَ فَهِيَ لَكَ
11/107 البداية والنهاية سنة أربعين من الهجرة النبوية فصل في ذكر شيء من سيرته العادلة وطريقته الفاضلة ومواعظه وقضاياه الفاصلة