Musnad Ahmad 8:138

Waki’ narrated to us, Sufyan narrated to us, from Habib ibn Abi Thabit, from Ibrahim ibn Sa’d, from Sa’d ibn Malik, and Khuzaymah ibn Thabit, and Usamah ibn Zayd, they said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Indeed, this plague is a punishment, or a remainder of a torment with which a people before you were tormented. So if it occurs in a land while you are in it, then do not depart from it fleeing from it. And if you hear of it in a land, then do not enter upon it."