Musnad Ahmad 30:3769

'Abd al-Rahman—meaning Ibn Mahdi—narrated to us, Jarir ibn Hazim narrated to us, he said: I heard al-Hasan narrating from Abu Hurayrah, from the Prophet, peace and blessings of Allah be upon him, who said: "Indeed, a man speaks a word, and he does not see that it reaches where it reached, [yet] he falls by it into the Fire for seventy autumns."