Musannaf Ibn Abi Shaybah 23818 — Those who permitted that

It is narrated from Babay, the freed slave of Sayyidah Umm Salamah or Sayyidah Aishah (may Allah be pleased with them both), who said: I saw Sayyiduna Sa'd (may Allah be pleased with him) carrying a basket of human excrement to a land of his called Zaghabah. I said to him: "O Abu Ishaq! Are you carrying this?" He said: "This basket of excrement and dung is in fact a basket of grain (food)."