Who is the person who died a Christian and whose body the earth spewed forth?

In the Two Sahihs, it is narrated on the authority of Anas (may Allah be pleased with him) that a man from Bani Al-Najjar used to write for the Prophet (peace be upon him). After he had read Al-Baqarah and Al-Imran, he apostatized and joined the People of the Book, who were impressed by him. However, he died, and every time they buried him, the earth would cast him out three times, so they left him abandoned. His name is unknown.