The Prophet, may the peace and blessings of Allah be upon him, sent the Abu Musa al-Ash'ari - 'Abd Allah ibn Qais Jad Sa'id ibn Abi Barda, may Allah be pleased with him, the narrator of this Hadeeth - and Mu'adh ibn Jabal as governors to two districts in Yemen. It was a part of his Sunnah to command the missionaries. Each of his commandments confirms and strengthens the other.