Praise be to Allah, and peace and blessings be upon the Messenger of Allah.
It is established in the Sunnah that the deceased is questioned by two angels in his grave. It is also established in a hadith that scholars have graded as hasan (good) that they are two angels who are black and blue, one of whom is called al-Munkar and the other an-Nakir. As for the detailed descriptions commonly mentioned—such as their eyes being like lightning, their voices being like thunder, and their digging the earth with their fangs—these have been reported in narrations that contain weakness. Therefore, one should not state these descriptions with certainty in the same way as descriptions established by authentic or hasan hadiths.
At-Tirmidhi narrated from Abu Hurayrah رضي الله عنه that the Prophet ﷺ said:
“When the deceased is buried—or he said: one of you—two angels who are black and blue come to him. One of them is called al-Munkar and the other is called an-Nakir…”
Al-Albani graded this hadith as hasan.
It mentions that the believer answers according to what he believed during his worldly life. He testifies that Muhammad ﷺ is the servant and Messenger of Allah, and his grave is then made spacious for him and illuminated.
As for the hypocrite, he says that he used to hear people saying something and would say the same thing as them, but he is unable to answer based on knowledge and faith.
A hadith has been reported from the Prophet ﷺ in a narration concerning his conversation with Umar ibn al-Khattab رضي الله عنه. It describes the two angels as digging the earth with their fangs, walking with their hair dragging behind them, and having eyes like lightning and voices like thunder.
However, this hadith has been narrated through weak chains, and some of its chains are mursal.
Some scholars considered that the multiplicity of its chains and supporting narrations could raise it to the level of hasan. Nevertheless, its chains are not as strong as the previously mentioned established hadith describing them as black and blue.
Therefore, with regard to matters of the unseen, it is safest to restrict ourselves to descriptions established by authentic or hasan evidence and not assert details that have not been clearly established.
It is established in the hadiths concerning the questioning in the grave that the deceased is asked about the foundations of his faith, including:
“Who is your Lord? What is your religion? And what do you say about the man who was sent among you?”
Allah grants the believer steadfastness, and he answers according to what he believed during his worldly life. As for the one whose faith was not firmly established, he is unable to answer.
This is among the meanings of the saying of Allah تعالى:
“Allah keeps firm those who believe with the firm word in the worldly life and in the Hereafter.”
[Ibrahim: 27]
What is established is that the deceased is questioned in his grave and that Munkar and Nakir are among the two angels assigned to this task. A hasan hadith describes them as black and blue.
As for the other well-known descriptions, such as their eyes being like lightning and their voices like thunder, they have been reported through narrations containing weakness. Although some scholars considered that their various chains may strengthen one another, these descriptions should not be asserted with the same certainty as matters that have been authentically established.
And Allah knows best.