Musnad Ahmad 1679

It was narrated that "Abdullah bin "Abbas said: "Umar bin al-Khattab set out, heading towards Syria... and he narrated the same haɗeeth. He said: ‘AbdurRahman bin "Awf was not there, then he came and said: I know something about this. I heard the Messenger of Allah (ﷺ) say: "If you hear of it being in some land, do not go there; if it occurs in some and and you are there, do not leave it, fleeing from it."