Tirmidhi

It is narrated from Abu Hurairah, may Allah be pleased with him, that the Prophet Muhammad, peace and blessings be upon him, said: "The Fire of Hell was kindled for a thousand years until it became red, then it was kindled for a thousand years until it became white, then it was kindled for a thousand years until it became black; now it is black and dark."

`Through this chain also,` a similar hadith is narrated from Abu Hurairah (may Allah be pleased with him), but it is not marfu‘ (attributed directly to the Prophet). © Imam Tirmidhi says:
The mawquf (stopped at the Companion) narration of Abu Hurairah (may Allah be pleased with him) in this chapter is more authentic. I do not know anyone who has narrated it as marfu‘ except Yahya ibn Abi Bukayr, who narrated it from Sharik.