Sunan Ibn Majah, Chapter: The Chapters on Ascetism (Zuhd)

that the Prophet (saw) said: "Allah will keep firm those who believe, with the word that stands firm." [14:27] This has been revealed concerning the torment of the grave. It will be said to him: Who is your Lord? He will say: My Lord is Allah, and my Prophet is Muhammad. This is what Allah says: Allah will keep firm those who believe, with the word that stands firm in this world (i.e. they will keep on worshipping Allah Alone and none else), and in the Hereafter (i.e., at the time of questioning in the grave)." [14:27]