Musnad Ahmad 33:1081

Abu Mu'awiyah narrated to us, from al-A'mash, from Abu Sufyan, from Jabir, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Some people from the people of Tawhid will be punished in the Fire until they become charcoal within it. Then, mercy will reach them, and they will be brought out and cast at the gate of Paradise. The people of Paradise will sprinkle water upon them, and they will sprout as the weeds sprout in the debris of a flood. Then, they will enter Paradise."