Musannaf Ibn Abi Shaybah 36030 — The affair of al-Qadisiyyah

Riyah said: The Muslim fighters found a grave in al-Mada'in containing a man who had on him garments with threads of gold and a great deal of wealth. The fighters brought it to Sayyiduna Ammar bin Yasir (may Allah be pleased with him). Sayyiduna Ammar wrote to Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) about this. Sayyiduna Umar ordered him: "Give all this wealth to the fighters, and do not take it back from them."