Some defined these ayat are descended about the groups of the unbelievers, in the Mecca when the prophet was reciting the ayaat of resurrection day to the Muslims. They were approaching from every nook and corner and forcefully telling: If there is a judgment day, that day our condition is better than those who brought faith in you, as our circumstances in this world is far better than you.

The noble Quran in their reply said: What is wrong with these unbelievers that they are coming to you in such a hurry?

فَمَالِ الَّذِينَ كَفَرُوا قِبَلَكَ مُهْطِعِينَ
(70:36
From the left and right they are coming in groups with the greed of heaven.
عَنِ الْيَمِينِ وَعَنِ الشِّمَالِ عِزِينَ
(70:37
Are they eagerly craving to enter the heaven, full of blessings?
أَيَطْمَعُ كُلُّ امْرِئٍ مِّنْهُمْ أَن يُدْخَلَ جَنَّةَ نَعِيمٍ
(70:38
Which deed and act they are hoping to deserve such a status for themselves.
مُهْطِعِينَ is the plural of مُهْطِع means the one who walks straight swiftly in proud with the neck held high and searching for something. Or sometimes it denotes that walks in proud with the neck held high to obtain some information.
عِزِينَ is the plural of the عِزِت means the disperse groups, as every group is in pursuit of its own aim and purpose.
Any way the egotistic and self centered polytheists were intensely declaring these baseless statements. Being well to do in their materialistic life, by the money which mostly achieved illegally by plundering the mankind. Having been successful in the materialistic life does not mean that he has a high status before the Merciful Allah and dear to Him. They believe that only by their meaningless judgment and think that they will possess an elevated position on the judgment day.
May be they were believing in the resurrection day but not according to the definition of the noble Quran. Sometimes they were discussing upon it, as a possibility that, if there is a judgment day then our position will going to be there in such and such way. Probably by telling this they may be thinking that they are making mockery of the believers.
Here the dignified Quran responded them and said: It never will happen like this that they are entering the gardens of the heaven overflowing with the blessings. As we have created them from a matter which they themselves distinguish what ( a worthless thing) it is.
In fact the Mighty Allah wants to crush down their pride and as it said: You know better that with what kind of matter we had formed you. From a putrid and low-quality water, valueless semen, then why to such a large extent there is overconfidence and pride in human being.
Secondly it is an answer to the ridiculers of the judgement day and said: if you have any doubt about the resurrection day, go and search the condition of the semen and observe how from a single valueless drop of water, we have created an extraordinary creature which every day by the evolutions of the fetus had become a new living thing.
Does the creator of the human being by the semen, is unable to wear a man the fresh apparel of life after his getting perished in the earth?

Thirdly how they have the greed of heaven when their book of deeds is filled with their evil acts? For the reason that he is the individual who is created by the worthless semen which not even have the materialistic importance. If they possess any worth, it is because of their right believe and the virtuous deeds. But they were devoid of such endeavour, then how they are expecting to step in the gardens of heaven?
Again to stress upon the matter it adds: I swear to the Allah of east and west. We are powerful.
فَلَا أُقْسِمُ بِرَبِّ الْمَشَارِقِ وَالْمَغَارِبِ إِنَّا لَقَادِرُونَ
(70:40

To change their place by the other people who are better than them and in this affair no one can overpower us.
Possibly this sentence may be indicating: we are not only dominant to bring them to the life after they had altered into the soil and give them a new life. But we can amend them into more perfect and better creatures and nothing can prevent us.

Or it may be pointing that there is no obstacle before us to destroy you in the punishment of your deeds and create the new true believers as your inheritor so that to be the supporters of our prophet peace be upon him.
Therefore if we are insisting upon you for bringing the faith, it is not for satisfying any need or weakness. But it is in the interest of the fulfilment of education and guidance of the mankind. The meaning of the “Allah of east and west” possibly illustrates that the Sovereign Allah is able to move the magnificent sun every day in a fresh mode from east to west. This function is accurate in such a manner that since millions of years it can travel without getting more or less. Likewise He is able to return again the man to life and bestow him a new existence or can destroy a group of people and make their inheritors a group of the capable people.