Commentary
Mentioned in the first two of the verses cited above is the punishment of disbelievers at the time of their death and the warnings given to them by the angels. Here, addressing the Holy Prophet ﷺ ، it has been said that had he seen the condition of the disbelievers at that time when the angels of Allah were beating their faces and backs as they extracted their souls and telling them to have a taste of the punishment of burning in the Fire, then, he would have seen some-thing awesome.
Some of the leading Commentators have declared this statement to be about the particular disbelievers from among the Quraysh who had come out to confront Muslims at the site of Badr where Allah Ta` ala had sent an army of angels to help Muslims. Thus, the meaning comes to be that the Quraysh chiefs who were killed in the battle of Badr were killed at the hands of the angels who were hitting them from the front on their faces and from the rear on their backs and were killing them in this manner while giving them the dark tidings of the punishment of Hell in the Hereafter.
Then, there are other Commentators who have kept the sense of this verse general in view of the generality of the words used in it. According to them, the verse means: When a disbeliever dies, the angel of death beats his face and back while taking out his soul. In some narrations, it appears that they have lashes of fire and maces of iron in their hands which they use to strike at the disbeliever condemned to death. But, as this punishment is not related to this world of elements, rather, is related to the universe of the grave which is known as Barzakh بَرزَخ (the post-death---pre-ressurrection state), therefore, this punishment is not generally seen optically.
Therefore, the modality used to address the Holy Prophet ﷺ was: 'And only if you were to see,' you would have seen a scene full of sobering lessons. This tells us that, after death, punishment is given to disbelievers while they are in the state of Barzakh, but that phenomenon is related to the universe of the Unseen کلام الغیب (` clam al-ghayb), therefore, it is not seen usually. The punishment of the grave finds mention in several other verses of the Holy Qur'an as well, while Hadith narrations on this subject just abound.