17. "Verily the Day of Sorting out is (a day) appointed".
18. "The Day when the Trumpet shall be blown and you shall come
forth in groups".
19. "And the heaven shall be opened and become (wide as) gates,"
20. "And the mountains shall be set in motion as if they were a mirage".
Finally, the Promised Day Will Come.
There were some various evidences for Resurrection referred to in the previous verses. Here, as a consequence, the first verse says: "Verily the Day of Sorting out is (a day) appointed,".
The phrase /yaum-al-fasl/ 'the Day of Sorting out' is a very meaningful one which speaks of isolations on that Great Day: The separation of Good from Evil, the separation of the believing good-doers from disbelieving sinners, the isolation of parents from child, and brothers from each other.
The term /miqat/ is based on the term /waqt/ 'time' which means 'an appointed time'. The certain places, where the pilgrims to Kaaba put on
their pilgrimage dress, are called /miqat/, because they gather there at an appointed time.
Then, some of the specialties and the events of that Great Day are detailed: "The Day when the Trumpet shall be blown and you shall come forth in groups".
It is well understood, from the verses of the Holy Qur'an, that two great events will happen "...when the Trumpet shall be blown". In the first incident, the order of the universe becomes disturbed and all the people, over the earth, and those who are in the heavens will die. In the second case the world will be renewed, the dead will return to life and the Resurrection will occur.
The term /nafx/ means 'blow' and the term /sur/ means 'trumpet' which is usually sounded for stopping or starting the caravans or troops, and the people, in them, understand this from its two different sounds whether they should stop or start.
This is a delicate point referring to those two great events. And what is said in the above verse, is a hint to the 'second blast', when 'the dead are revived and the Resurrection occurs'.
This verse says that on that Day, "...you shall come forth in groups", while Sura Maryam, No. 19, verse 95 says: "And every one of them will come to Him singly on the Day of Judgment" and, also, Sura Asra, No. 17, verse 71 says: "One day We shall call together all human beings with their (respective) Imams...".
To collect these senses together, we see that 'people being in groups' is not in contrast with 'every group enters the Resurrection with its respective Imam'. And 'every one of them will coming singly' is stated for the reason that there are several stopovers in the Hereafter. People may come in groups with their respective leaders; leading or misleading, at the first halting places, but when they stand before the throne of Justice, they stand individually, or as Sura Qaf, No. 50. verse 21 says: "And there will come forth every soul: with each will be an (angel) to drive and an (angel) to bear witness".
It is also probable that they come one by one, because they are separated from their friends, partners and supporters Since, in the Hereafter, everyone is alone with one's own deeds.
"And the heaven shall be opened and becomes (wide as) gates".
What are the meanings of 'be opened' and 'gates'?
Some commentators have said that it means that the doors of the 'unseen world' will be opened to the 'intuition world' where the curtains will be removed, thus making the world of angels open to the world of Man.
Some others think that this verse points to what is said in other verses of the Holy Qur'an, such as in Sura Inshiqaq, No. 84 verse 1 which says: "When the Sky is rent asunder", and on another occasion in relation to the same sense, but using another word it says: "When The Sky is cleft asunder" (Sura Infitar, No. 82 verse 1).
In fact, there will appear so many clefts in the celestial spheres that it will seem as if they have changed into open gates.
There is another probability that Man, in the present conditions of this world, cannot venture through the heavens, and if it were possible for him to, it would be strictly limited, as if, the present circumstances had shut the gates of the skies to him. But, in the Hereafter, Man will become free from the earthly world and the gate-ways to the heavens will be opened to him, and then the necessary conditions will become available.
In other words, on that Day, the skies will be 'cleft asunder' and after that new skies and earth will be substituted, as Sura Ibrahim, No. 14, verse 48 says: "One day the Earth will be changed (into) a different Earth and so will be the heavens...". On this occasion the gates of the skies are opened for the earthly men to go through and follow their ways: the righteous go into Heaven whose doors will be opened to them: "...until behold, they arrive there; its gates will be opened; and its keepers will say: Peace be upon you..." (Sura Zumar, No. 39 verse 73).
It is in the same place that angels come to them from every door and congratulate them: ", and angels shall enter unto them from every gate (with the salutation), (Sura Rad, No. 13, verse 23).
And the doors of Hell will he opened to the Unbelievers: "The Unbelievers will be led to Hell in crowds: until when they arrive there, its gates will he opened...", (Sura Zumar, No. 39, verse 71).
And. thus, Man arrives in a place where the width is as wide as the phenomenal earth and heavens: "...and for a garden whose width is that (of the whole) of the heavens and of the earth..." (Sura Al-i-Imran, No. 3, verse 133).
And finally, the next verse, explaining the events of the Hereafter, illustrates the status of the mountains and says: "And the mountains shall vanish as if they were a mirage".
As it is understood from all the different verses of the Qur'an about 'the end of the mountains in the Hereafter', that mountains will go through stages: at first they will move: "And the mountains are in motion", (Sura Tur. No. 52, verse 10).
Then they will be taken off and crushed: "...and the earth and mountains are lifted up and crushed with a single blow", (Sura Haqqah, No. 69, verse 14).
And after that they will be as a poured heap of sand: "...and the mountains become a slipping heap of sand", (Sura Muzzammil, No. 73, verse 14).
Then, they will change like fibers of teased or carded wool which can be moved about by the winds: "And the mountains will be like carded wool", (Sura Al-Qariah, No. 101, verse 5).
They will turn to dust, then, and scatter about: "And the mountains shall be crumbled to atoms", "Becoming dust scattered abroad", (Sura Waqiah, No. 56, verses 5-6)
And finally, as the current verse denotes, there will remain only a trace of them as a mirage. Thus, mountains will disappear throughout the earth at last, and the land will be level: "They ask you concerning the Mountains: say, My Lord will uproot them and scatter them as dust"; "He will leave them as plains smooth and level", (Sura Ta-Ha, No. 20. verses 105-106).
The term /sarab/ is based on the term /sarab/ and means: 'a mirage', a deceitful appearance as of water in the desert. Then anything that has an appearance, but is nothing, indeed, is called 'mirage'.
In fact, the mountains will turn into dust and will be scattered in the air in a state like a mirage. When high solid mountains will have a destiny like this, the state of other changes in the world and, also, the state of people of great authority, in this life, will be obvious there; a mere mirage.
The following question may arise: Do these events happen with the 'first blast', which is the end of this world, or with the 'second blast', which is the beginning of the Resurrection?
Since the verse "The Day when the trumpet shall be blown and you shall come forth in groups" certainly relates to the 'first blast', when people survive and arrive at the Hereafter in groups, this verse must be concerned with the same blast, too, but its beginning (the movement of the mountains) may occur with the 'first blast' and its end (changing as a mirage) with the 'second blast'
There is another probability that all the stages of the mountains relate to the first blast, however, since the range of these two blasts are almost close to each other, they are mentioned together, as in some other verses of the Qur'an. The events of the first blast are mentioned with the events of the second blast (as in Suras Takwir and Infitar).
It is noteworthy that in the former verses mountains were referred to as 'pegs' and the earth as a 'cradle'; but in these verses it is said that on the Day when the order of the destruction of this world will be issued, that cradle will be disturbed and those great pegs will be leveled and, hence, their tangible matter will become decomposed and shattered.
 Al-Mizan,, vol. 20, p. 265 (Farsi