Musannaf Ibn Abi Shaybah 23159 — Judging between Jews and Christians

Sayyiduna Ali (may Allah be pleased with him) sent Sayyiduna Muhammad bin Abi Bakr (may Allah be pleased with him) as governor of Egypt. Sayyiduna Muhammad (may Allah be pleased with him) wrote to Sayyiduna Ali (may Allah be pleased with him), asking: A Muslim has committed adultery with a Christian woman; what is the ruling on this? Sayyiduna Ali (may Allah be pleased with him) wrote in reply: Carry out the prescribed punishment (hadd) on the Muslim who committed adultery with the Christian woman, and hand the Christian woman over to the Christians, so that they may decide about her as they wish.