Sahih Bukhari | Volume 8 | Hadith Number 654
Narrated by Anas bin Malik
The Prophet said, "The Hell Fire will keep on saying: 'Are there anymore (people to come)?' Till the Lord of Power and Honour will put His Foot over it and then it will say, 'Qat! Qat! (sufficient! sufficient!) by Your Power and Honour. And its various sides will come close to each other (i.e., it will contract)."