[Machine] The Messenger of Allah ﷺ sent Ali ibn Abi Talib and Khalid ibn al-Walid to Yemen and said, "When you are together, I am the leader, and when you separate, each of you is responsible for his own work." Khalid ibn al-Walid wrote to the Prophet ﷺ and started with himself, and the Prophet ﷺ did not object to that. Ali also wrote to the Prophet ﷺ and he was pleased with him, so he started with the Prophet ﷺ .  

أَنَّ رَسُولَ اللهِ ﷺ بَعَثَ عَلِيَّ بْنَ أَبِي طَالِبٍ وَخَالِدَ بْنَ الْوَلِيدِ ؓ إِلَى الْيَمَنِ وَقَالَ «إِذَا اجْتَمَعْتُمَا فَعَلَيٌّ الْأَمِيرُ وَإِذَا تَفَرَّقْتُمَا فَكُلُّ وَاحِدٍ مِنْكُمَا عَلَى عَمَلِهِ» وَكَتَبَ خَالِدُ بْنُ الْوَلِيدِ إِلَى النَّبِيِّ ﷺ فَبَدَأَ بِنَفْسِهِ فَلَمْ يُنْكِرْ ذَلِكَ عَلَيْهِ وَكَتَبَ عَلِيٌّ إِلَى النَّبِيِّ ﷺ وَرَضِي عَنْهُ فَبَدَأَ بِالنَّبِيِّ ﷺ