(Let him then bring us an Ayah like the ones (Prophets) that were sent before (with signs)!) 21:5 We mentioned this subject several times before and stated that Allah is able to bring them what they wanted. There is a Hadith which mentions that the idolators asked the Prophet to turn Mount As-Safa into gold and, they also asked him for a spring to gush forth for them and to remove the mountains from around Makkah and replace them with green fields and gardens. Allah revealed to His Messenger : "If You wish, O Muhammad, I will give them what they asked for. However, if they disbelieve thereafter, I will punish them with a punishment that I did not punish any among the `Alamin (mankind and the Jinns). Or, if you wish, I will open for them the door to repentance and mercy." The Prophet said,
At the beginning of the section, human beings were divided into two kinds - those who are obedient to Allah Ta’ ala and those who are disobedient to Him. Then, enumerated there were some attributes and signs of the obedient servants of Allah and mention was made of the best of rewards for them in the Hereafter.
Now, in the present verses, stated there are the attributes and signs, and punishments, of the other kind of people. One trait of character these disobedient and contumacious people have been reported to have الَّذِينَ يَنقُضُونَ عَهْدَ اللَّـهِ مِن بَعْدِ مِيثَاقِهِ (And those who break [ their ] pledge with Allah after it has been made binding). Included here is the pledge out of the pledges given to Allah concerning His unshared Lordship and Oneness by all spirits created by Him. The disbelievers and polytheists broke this pledge when they came into this world and consequently took to hundreds and thousands of lords and objects of worship all joined up with the pristine divinity of Allah Ta` ala.
Man is bound to God by the bond of nature and to his fellow beings by the bond of humanity. Breaking both bonds leads to creating mischief on God’s earth. Living a peaceful life on God’s earth means making his life subject to the above-mentioned bonds. In liberating himself from these bonds – caring nothing for the rights of God or men—he only creates mischief. Those who act thus incur the curse of God. Such as these will not share in the Grace of God. They have fouled God’s earth, so they deserve to be pushed into the foulest of places—Hell. In this world one receives less and another receives more. The one who receives more develops a superiority complex, while the one who receives less suffers from an inferiority complex. But, in the eyes of God, neither attitude is correct. The correct reaction is that if one receives more, he should become grateful to God; one who receives less, should strive to remain patient and be contented with what he has. Worldly-oriented people invariably ignore the preacher of Truth. The reason for this is that a worldly person recognizes only worldly glories. As the preacher is in possession of only sublime truths, he is not recognized and is ignored as an unimportant person. But, when the veil over reality is torn asunder, man will come to know at that time that the apparent glory which he considered everything, was absolutely valueless. The truly valuable thing was reality which, because it was unseen, could not claim his attention.
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.