The following is a letter which Imam Ali (a) wrote to Umar bin Abi Salama Mukhzumi when Imam Ali (a) called him back from the Governorship of Bahrain and appointed Nuíman bin Ajlan Zuraqi in his place.
After glorifying Allah and praising the Holy Prophet (s) let it be known to you that I have appointed Nuíman as the Governor of the province of Bahrain and have removed you from the post not because I was dissatisfied with your work or there was any charge against you. Undoubtedly you have discharged your duties satisfactorily and have done full justice to the trust reposed in you. I am quite satisfied with your work and I neither doubt your honesty nor do I consider you to be inefficient and blameworthy.
Come to me immediately. The fact is that I have resolved to face the Syrian tyrants and oppressors and I want you to be with me because you are one of those men whom I can trust to help me in facing the enemies of Allah and in the establishment of the Islamic State.