Musannaf Ibn Abi Shaybah 36159 — Book of History

Sayyiduna Abu Thawr al-Fahmi (may Allah be pleased with him) said: Sayyiduna Abd al-Rahman bin Udays (may Allah be pleased with him), who took part in the Pledge of Ridwan, came to us. He ascended the pulpit, praised and glorified Allah, and then mentioned Sayyiduna Uthman (may Allah be pleased with him). Sayyiduna Abu Thawr (may Allah be pleased with him) said: Then we went to Sayyiduna Uthman (may Allah be pleased with him) while he was under siege, and Sayyiduna Uthman (may Allah be pleased with him) said: I am the fourth to have accepted Islam.