The Messenger of Allah ﷺ said, "This fire of yours, the one the children of Adam kindle, is but one part in seventy of the heat of Hell."They said, "By Allah, this fire alone would surely be enough, Messenger of Allah."He replied, "Yet Hell exceeds it by sixty-nine parts, each one as hot as this fire."
وقال رسول الله ﷺ ناركم هذه ما يوقد بنو آدم جزء واحد من سبعين جزءا من حر جهنم قالوا والله إن كانت لكافية يا رسول الله قال فإنها فضلت عليها بتسع وستين جزءا كلهن مثل حرها
This is sahih by the soundness of what precedes it, and it is in the individual Sahifah under number 12. Muslim [8:150 S / 2:352 Bulaq] related it through the transmission lines of the Sahifah, but did not give its wording, referring instead to the narration before it, which comes through the recension of Araj. Bukhari related it, 6:238 Fath, through the recension of Araj. Its meaning has already passed, with some addition and omission, through the recension of Araj, 7323. The wording given here almost matches the wording of the Sahihayn and the Muwatta [p. 994], through the recension of Araj.