16. "Did We not destroy the men of old?"
17. "Then shall We make following (generations) follow them."
18. "Thus do We ever deal with men of sin."
19. "Ah woe, that Day, to the Rejecters of Truth."
20. "Did We not create you from a base fluid?"
21. "The which We placed in a safe abode; (firmly fixed)."
22. "For a period (of gestation) determined?"
23. "For We determine; and We are the best to determine (and then
Resurrection is easy for Us to portend)"
24. "Ah woe, that Day, to the Rejecters of Truth!"
25. "Have We not made the earth (as a place) to draw together?"
26. "Both for the living and the dead,"
27. "And placed therein high mountains standing firm, and given you to drink (wholesome) sweet water?"
28. "Ah woe, that Day, to the Rejecters of Truth!"
They see these Signs of Power, yet they reject the Resurrection!
Through these verses, Rejecters are warned in different ways and by various statements.
First, they are reminded of the old generation's fate: "Did We not destroy the men of old?"
In our own times we can observe relics of old civilizations. Generations such as those of the 'Ad, the Thamud, Noah's, Lot's and Pharaoh's were destroyed as punishment for their evil deeds; partly by flood, lightning and hurricane, and some generations by earthquakes and meteorites.
"Then shall We make following (generations) follow them."
Allah's Law is always the same. Sin or corruption prepares its own destruction. Should some be punished for sinning while others not?
"Thus do We ever deal with men of sin."
In fact, this verse is a confirmation to the destruction of the old generations and for the present and future generations, as well. Since Allah's punishment is neither for revenging nor settling His own personal account, it, therefore, depends on their own sinful deeds and on His superior wisdom.
Some believe that the word /awwalin/ 'old', in this verse, refers to the generations of Noah, 'Ad and Thamud; and the word /akharin/ 'following' refers to the generations after them; such as those of Lot and Pharaoh. But taking note of the term /nutbi'uhum/ "..shall we make follow (generations) follow them", which is in the future tense and /alam nuhlik/ "Did We not destroy...", which is in past tense it, then, becomes clear that 'old' refers to all the old generations who were destroyed by Allah's Will, and 'following' refers to the sinners of the Prophet's (p.b.u.h.) time or those who will come into being after that and will commit sins and corruptions.
And, so, the warning: "Ah woe, that Day, to the Rejecters of Truth." The words 'that Day' here, means the Hereafter, when they will have their main punishment and retribution. The repetition of the verse is for emphasis, though they may have a chastisement even in this world.
Then, it attracts their attention to the period of gestation which shows them the power and the authority of the Creator and also the abundance of His blessings to Man. Consequently, they understand His force, in regard to the Resurrection, and, they, themselves, owe Allah for His numerous blessings and respect Him.
"Did We not create you from a base fluid?"
"The which We placed in a safe abode, (firmly fixed)".
A place where all the conditions for life, growth and protection of the fetus exist. It is so amazing and interesting that it causes everyone to wonder.
"For a period (of gestation) determined?"
A period of time that no one knows, but Allah. During this period many changes occur and every day the fetus enters a new phase in its development in that abode.
"For We determine; and We are the best to determine, (and then Resurrection is easy for Us to portend)".
This is the same reason for which the Qur'an has emphatically used in proving the possibility of the Resurrection. For example, in the beginning verses of Sura Hajj, No. 22, Mankind's attention is attracted to the process of their own physical growth; from lifeless matter to seed, fertilized ovum, fetus, child, youth, aged and death! How can they doubt that the author of all these wonderful stages in their lives, in this world, each of which is as important as the Resurrection, can also give them another kind of life after the end of this probationary life? How different is dust from sperm!
"Ah woe, that Day, to the Rejecters of Truth".
Woe to those who see these numerous wonders of His power and yet they deny Him.
In this respect, Imam Ali (p.b.u.h.) has said: "O creature who has been equitably created and who has been nourished and looked after in the darkness of wombs with multiple curtains. You were originated from the essence of clay and put in a quiet place for a determined length and ordained time. You used to move in the womb of your mother as an embryo, neither responding to a call nor hearing any voice".
"Then you were taken out from the place in which you stayed to a place that you had not seen, and you were not acquainted with awaiting its benefits. Who guided you to obtain your sustenance from the milk of your mother's breast? Who taught you to express your demands with your cries? Verily, when you cannot fully understand your own self, how can you understand your Creator? It is impossible for you to understand Allah from the attributes which are meant only for His creatures."
In another part of the verses, the external nature and His blessings, in this great world, are described. These are proofs for both His authority and Mercy, and for the reality of Resurrection, while the former verses were about the creation of Man himself.
"Have We not made the earth (as a place) to draw together?"
"Both for the living and the dead".
The term /kifat/  'a place where things are gathered together' is derived from /kaft/ which means 'to gather together', or 'to attach one thing to another'. 'Birds flying fast' is also called /kifat/, since when they fly fast they gather their wings to their sides in order to move more quickly through the air.
It intends to say: Earth is a gathering place for all human beings; it gathers the living men and women over itself and gives them their needs totally, and envelops their dead bodies in its insides. If the ground were not fit for burial, the bad smell and various diseases would arise from the corpses and this would be a disaster for the living ones.
Yes, the land, like a mother who gathers her children around her, gathers individuals over itself, caresses them, feeds them, dresses them, gives them residence, gives them all their needs, keeps their corpses in its inside, dissolves them and then causes their harmful effects to vanish.
Some commentators have used /kifat/ in the sense of 'to fly quickly' and have said that the term refers to the Earth's rotation around the Sun, and other movements, all of which were not known by people at the time of revelation of the Qur'an.
In the next verse, that is: "...the living and the dead", it seems that the first meaning is more suitable. Particularly, if we consider the following narration from Imam Ali (p.b.u.h.). When he was coming back from the Seffin Battlefield he reached a cemetery outside the gate of Kufa. He looked across it and said: "This is the abode of the dead and where they dwell", and then he looked towards the houses of the city and said: "This is the abode of the living". He wanted to tell others that there is not a long distance between the abode of the living and that of the dead, then, he recited the above verses: "Have We not made the earth (as a place) to draw together?" "Both for the living and the dead." 
Then, the Qur'an mentions one of the great blessings of Allah on the earth:
"And placed therein high mountains standing firm,..."
These high mountains and their underlying formations united together, on the one hand, protect the earth, armor-like, against the inner pressures and the pressures resulting from gravity and, on the other hand, they prevent the air's friction with the land by providing a break in the air mass with their peaks, and thirdly, they control the violent winds and storms. Then, in this way, they afford peace and comfort to the earth's dwellers.
And, at the end of this verse, another gift from the mountains is cited:
"....and given you to drink wholesome sweet water?"
The 'wholesome sweet water' is useful and lively both for 'you' and for 'your' animals, agriculture, and gardens.
It is true that all the sources of sweet water are from rain, but mountains play the primary role in supplying life with water: many headsprings and aqueducts stem from mountains; many of the rivers and streams originate from the heavy thick melting snow on the high mountains tops.
The tops of the mountains, because of their altitude, are the most useful for human beings, as they are far from the plains surface and they are always cold. They can keep the snow there for years and then the sun melts the snow, gradually, flowing into the streams.
The refrain is repeated: "Ah woe, that Day, to the Rejecters of Truth."
It is they who see these signs and the types of His Bounty and Power; the blessings by which they are continually benefited and, yet, deny the Resurrection, His Justice and His Wisdom.
 Nahj-ul-Balaqa, Sermon No. 162 (Arabic Version); Sermon No. 166 (English Version).
 /Kifata/ is the second object for its verb, and is infinitive; used as a subjective noun.
 Tafsir-i-Borhan, vol. 4, p.