Musannaf Ibn Abi Shaybah 27531 — A man who writes: Amma ba'd

Ibn Abi Layla said that Sayyiduna Abu al-Darda (may Allah be pleased with him) wrote a letter to Sayyiduna Maslamah bin Mukhallad (may Allah be pleased with him), who was the governor of Egypt, and in it he wrote: "Amma ba'd (to proceed)."