Musnad Ahmad 31:785

Musa ibn Dawud narrated to us, Ibn Lahi'ah informed us, from Darraj, from Abu al-Haytham, from Abu Sa'id al-Khudri, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "If a mountain were struck with a mace of iron, it would crumble and then return to how it was. And if a bucket of *ghassaq* (the foul discharge of the people of Hell) were poured into the world, it would cause the people of the world to stink."