Musnad Ahmad 30:1863

'Affan narrated to us, Hammad narrated to us, Yahya bin Sa'id informed us, from Sa'id bin Yasar, from Abu Hurairah, that the Messenger of Allah (ﷺ) said: "I have been commanded to a town that eats the towns, and it expels the filth, just as the bellows expels the filth of iron."