Sahih Muslim Book 020, Hadith Number 4490.
Chapter : Prohibition of desire for a position of authority and covetousness thereof.
It has been reported on the authority of Abu Musa who said: I went to the Holy Prophet (may peace be upon him) and with me were two men from the Ash'ari tribe. One of them was on my right hand and the other on my left. Both of them made a request for a position (of authority) while the Holy Prophet (may peace be upon him) was brushing his teeth with a tooth-stick. He said (to me): Abu Musa (or 'Abdullah b. Qais), what do you say (about the request they have made)? I said: By God Who sent thee on thy mission with truth, they did not disclose to me what they had in their minds, and I did not know that they would ask for a position. The narrator says (while recalling this hadith): I visualise as if I were looking at the miswak of the Holy Prophet (may peace be upon him) between his lips. He (the Holy Prophet) said: We shall not or shall never appoint to the public offices (in our State) those who with to have them, but you may go, Abu Musa (or Abdullah b. Qais) (to take up your assignment). He sent him to Yemen as governor, then he sent Mu'adh b. jabal in his wake (to help him in the discharge of duties). When Mu'adh reached the camp of Abu Musa, the latter (received him and) said: Please get yourself down; and he spread for him a mattress, while there was a man bound hand and foot as a prisoner. Mu'adh said: Who is this? Abu Musa said: He was a Jew. He embraced Islam. Then he reverted to his false religion and became a Jew. Mu'adh said: I won't sit until he is killed according to the decree of Allah and His Apostle (may peace be upon him) (in this case). Abu Musa said: Be seated. It will be done. He said: I won't sit unless he is killed in accordance with the decree of Allah and His Apostle (may peace be upon him). He repeated these words thrice. Then Abu Musa ordered him (to be killed) and he was killed. Then the two talked of standing in prayer at night. One of them, i.e. Mu'adh, said: I sleep (for a part of the night) and stand in prayer (for a part) and I hope that I shall get the same reward for steeping as I shall get for standing (in prayer).