Musnad Ahmad 1536

Habeeb bin Abi Thabit said: I came to Madinah and we heard that the plague had broken out in Koofah. I said: Who narrated this Hadeeth? It was said: "Amir bin Sa"d, And it was said: He was not there. Then i met Ibraheem bin Sa"d and he told me that he heard Usamah bin Zaid tell Sa"d that the Messenger of Allah (ﷺ) said: "If the plague breaks out in a land, do not enter it, and if it breaks out in a land where you are, do not leave it." I said: Did you hear it from Usamah? He said: Yes.