عَنْ عَلِيٍّ رَضِيَ اللَّهُ عَنْهُ قَالَ: بَعَثَنِي رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ إِلَى الْيَمَنِ (يَعْنِي قَاضِيًا) وَأَنَا حَدِيثُ السِّنِ، قَالَ: قُلْتُ: تَبْعَثُنِي إِلَى قَوْمٍ يَكُونُ بَيْنَهُمْ أَحْدَاثٌ وَلَا عِلْمَ لِي بِالْقَضَاءِ، قَالَ: ((إِنَّ اللَّهَ سَيَهْدِي لِسَانَكَ وَيُثَبِّتُ قَلْبَكَ)) قَالَ: فَمَا شَكَكْتُ فِي قَضَاءٍ بَيْنَ اثْنَيْنِ
It is narrated from Sayyiduna Ali (may Allah be pleased with him), he says: The Messenger of Allah (peace and blessings be upon him) appointed me as a judge to Yemen, while I was still young, so I said: O Messenger of Allah! You are sending me to a people among whom new matters arise, and I do not have knowledge of judging. The Prophet (peace and blessings be upon him) said: Allah Almighty will guide your tongue and strengthen your heart. After that, I never felt any doubt or uncertainty when deciding between two people.