Silsilat al-Ahadith al-Sahihah

It is narrated from Sayyiduna Bara’ bin ‘Azib (may Allah be pleased with him) that the Messenger of Allah (peace and blessings of Allah be upon him) said: “When a believer is made to sit in his grave and the angels come to him, he bears witness that Allah alone is the true deity and Muhammad (peace and blessings of Allah be upon him) is the Messenger of Allah. Allah Almighty has indicated this matter in His saying: ‘Allah keeps firm those who believe, with the firm word.’ This verse was revealed regarding the punishment of the grave.” In another narration it is stated: “When a Muslim is questioned in the grave, he responds by bearing witness that there is no deity worthy of worship except Allah and Muhammad (peace and blessings of Allah be upon him) is the Messenger of Allah. This is in accordance with the saying of Allah Almighty: ‘Allah keeps firm those who believe, with the firm word, in the life of this world and in the Hereafter.’” (Surah Ibrahim: 27)