Musnad Ahmad 30:1045

The Messenger of Allah, may Allah bless him and grant him peace, said: "Paradise and Hell disputed. Hell said: 'I have been favored with the arrogant and the tyrants.' Paradise said: 'Why is it that none enter me except the weak among the people, the lowly, and the simpletons?' Allah, the Almighty and Majestic, said to Paradise: 'You are only My mercy; I show mercy through you to whom I will of My servants.' And He said to Hell: 'You are only My punishment; I punish through you whom I will of My servants. And for each of you is its filling.' As for Hell, it will not be filled until Allah, the Almighty and Majestic, places His foot into it, whereupon it will say: 'Enough, enough'—meaning: 'It is sufficient for me.' At that point, it will be filled, and its parts will draw together. Allah does not wrong any of His creation. As for Paradise, Allah will create for it a new creation."