Musnad Ahmad

It is narrated from Hazrat Anas (may Allah be pleased with him) that there was a man who used to write for the Prophet (peace and blessings be upon him). He had also memorized Surah Al-Baqarah and Aal-e-Imran. The Prophet (peace and blessings be upon him) would dictate to him "Sami'an" and he would write "Sami'an Basiran" instead. The Prophet (peace and blessings be upon him) would say, "Write it like this," but he would say, "I will write as I wish." Similarly, when the Prophet (peace and blessings be upon him) would dictate "Aleema," he would write "Aleema Hakeema" instead. After some time, that man became an apostate and turned Christian, and began to say, "I used to write whatever I wanted for Muhammad (peace and blessings be upon him) among you all." When that man died, he was buried, but the earth threw him out. Hazrat Anas (may Allah be pleased with him) says that Hazrat Abu Talha (may Allah be pleased with him) told me that he went to the place where that man had died and found him lying outside.