Musannaf Ibn Abi Shaybah 36015 — The affair of al-Qadisiyyah

Husayn reports from one of the fighters who took part in the Battle of al-Qadisiyyah that a man was bathing when he found a brick of gold in the water. He brought it and gave it to Sayyiduna Sa'd (may Allah be pleased with him). Sayyiduna Sa'd said: "Put it among the spoils of war."