مُسْنَدُ أَحْمَدَ
Musnad Ahmad 1508
Musnad Abu Ishaq Sa'd bin Abi Waqqas
It was narrated from Sa"d (رضي الله عنه), from the Prophet (ﷺ) that He said concerning the plague: "If it occurs in a land, do not enter it, and if you are in (that land), do not flee from it.”
Musnad Ahmad 1508Sahih hadeeth]