A Comprehensive Chapter on the Proofs of Prophethood:

Sulayman ibn al-Mughira narrated from Thabit, from Anas, who said: “There was among us a man from the Banu al-Najjar who had learned Surah al-Baqarah and Surah Al-‘Imran and who used to write for the Messenger of Allah, peace and blessings be upon him. The man fled until he reached the People of the Book. They promoted him, saying, ‘This man used to write for Muhammad,’ and they were impressed by him. It was not long before Allah broke his neck while he was among them. They dug a grave for him and buried him, but the next morning the earth had thrown him out onto its surface. They dug again and buried him, yet by morning the earth had cast him out once more. They buried him a third time, and again the earth expelled him, so they left him lying exposed.” Reported by Muslim.

‘Abd al-Warith narrated from ‘Abd al-‘Aziz, from Anas, who said: “A man who was a Christian embraced Islam and memorized Surah al-Baqarah and Surah Al-‘Imran. He used to write for the Prophet, peace and blessings be upon him. Later he reverted to Christianity and would say, ‘Muhammad knows nothing except what I used to write for him.’ Allah caused him to die, and they buried him. In the morning the earth had spewed him out. They said, ‘This is the doing of Muhammad and his companions.’ So they dug his grave deeper and buried him again, yet the earth spewed him out the next morning. They repeated the burial, digging as deep as they could, but by the following morning the earth had thrown him out once more. Only then did they realize that it was an act of Allah.” Recorded by al-Bukhari.

Al-Layth narrated from Sa‘id al-Maqburi, from his father, from Abu Hurayra, that the Messenger of Allah, peace and blessings be upon him, said: “There has never been a prophet among the prophets except that he was given signs by which…”