Musnad Ahmad 31:854

Rawh narrated to us, Ibn Jurayj narrated to us, Abu al-Zubayr informed me, from Abu Sa’id, that he heard the Prophet, peace and blessings of Allah be upon him, saying: "People will emerge from the Fire having been burnt, and they will be like charcoal. Then the people of Paradise will continue to sprinkle water upon them, until they grow like the growth of the scum in a flood."