Narrated Al-Bara' bin 'Azib (may Allah be pleased with him): The Prophet (peace and blessings of Allah be upon him) said: When a believer is made to sit in his grave, angels come to him. He bears witness that there is no deity except Allah and that Muhammad (peace be upon him) is the Messenger of Allah. This is the interpretation of Allah's statement in Surah Ibrahim, that Allah keeps firm those who believe, with the firm word (of faith) in the life of this world and in the Hereafter, meaning He keeps them steadfast on monotheism.