Sahih al-Bukhari 4341, 4342

Narrated Abu Burda:Allah's Messenger (ﷺ) sent Abu Musa and Mu`adh bin Jabal to Yemen. He sent each of them to administer a province as Yemen consisted of two provinces. The Prophet (ﷺ) said (to them), "Facilitate things for the people and do not make things difficult for them (Be kind and lenient (both of you) with the people, and do not be hard on them) and give the people good tidings and do not repulse them. So each of them went to carry on his job. So when any one of them toured his province and happened to come near (the border of the province of) his companion, he would visit him and greet him. Once Mu`adh toured that part of his state which was near (the border of the province of) his companion Abu Musa. Mu`adh came riding his mule till he reached Abu Musa and saw him sitting, and the people had gathered around him. Behold! There was a man tied with his hands behind his neck. Mu`adh said to Abu Musa, "O `Abdullah bin Qais! What is this?" Abu Musa replied. "This man has reverted to Heathenism after embracing Islam." Mu`adh said, "I will not dismount till he is killed." Abu Musa replied, "He has been brought for this purpose, so come down." Mu`adh said, "I will not dismount till he is killed." So Abu Musa ordered that he be killed, and he was killed. Then Mu`adh dismounted and said, "O `Abdullah (bin Qais)! How do you recite the Qur'an ?" Abu Musa said, "I recite the Qur'an regularly at intervals and piecemeal. How do you recite it O Mu`adh?" Mu`adh said, "I sleep in the first part of the night and then get up after having slept for the time devoted for my sleep and then recite as much as Allah has written for me. So I seek Allah's Reward for both my sleep as well as my prayer (at night).