Musnad Ahmad 32:1190

Ibn Abi ‘Adi narrated to us, from Humayd, who said: Anas was asked about the punishment of the grave, and he said: "The Prophet, peace and blessings of Allah be upon him, used to seek refuge, saying: 'O Allah, I seek refuge in You from laziness and old age, and cowardice and stinginess, and the trial of the Dajjal, and the punishment of the grave.'"