Musnad Ahmad

Habib bin Abi Thabit says that once I had come to Madinah Munawwarah, and I received news from behind that a plague had broken out in Kufa. I asked people, "Who narrates the hadith on this subject here?" People mentioned the name of Amir bin Sa’d, but he was not present there at that time. Then I met Ibrahim bin Sa’d, and he narrated to me, on the authority of Sayyiduna Usamah bin Zaid (may Allah be pleased with them both), the narration of Sayyiduna Sa’d (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "When a plague spreads among a people, do not go there, and if you are already present in an area and a plague breaks out there, then do not leave from there." I asked Ibrahim, "Did you hear this narration directly from Sayyiduna Usamah (may Allah be pleased with him)?" He replied in the affirmative.