The Messenger of Allah ﷺ said, "Allah Most High will bring out a people from the Fire after they have been scorched in it and turned to charcoal. They will be cast into a river at the gate of Paradise called the River of Life, and they will sprout in it as a seed sprouts in the silt carried by a flood, or as wild herbs sprout. Then they will enter Paradise, and it will be said, 'These are Allah's freed ones from the Fire.'"A man suspected of holding the views of the Khawarij, called Harun Abu Musa, or Abu Musa bin Harun, said, "What is this that you are narrating, Abu Asim?"He replied, "Get away from me, you brute! Had I not heard it from more than thirty of the Companions of the Messenger of Allah ﷺ, I would not have narrated it."
قال رسول الله ﷺ: يخرج الله تعالى قوما من النار بعدما امتحشوا فيها، وصاروا فحما، فيلقون في نهر على باب الجنة، يسمى نهر الحياة، فينبتون فيها كما تنبت الحبة في حميل السيل، أو كما تنبت الثعارير، فيدخلون الجنة، فيقال: هؤلاء عتقاء الله عز وجل من النار. وقال رجل متهم برأي الخوارج، يقال له هارون أبو موسى أو أبو موسى بن هارون: ما هذا الذي تحدث به أبا عاصم؟ فقال: إليك عني يا علج! فلو لم أسمعه من أكثر من ثلاثين من أصحاب رسول الله ﷺ لم أحدث به.
Narrated by Ibn Abu Umar in Matalib Aliyah (4560), and this is his wording, and by Bayhaqi in Shuab al-Iman (319), both of them by way of Sufyan bin Uyayna, from Amr bin Dinar, who said that he heard Ubayd bin Umayr say what has already been mentioned. Its chain of transmission is sahih.Ubayd bin Umayr belongs to the generation after the companions, and his statement, "The Messenger of Allah ﷺ said," is a mursal report. However, he stated explicitly at the end of the hadith that he heard it from more than thirty companions. And it is as he said, for it has been narrated by a group of the companions, and the sahih narrations among them have been mentioned in Jami Kamil.