Described in the second verse (115), there are two more distinctive qualities of the Holy Qur'an sufficient to prove its being the Divine Word. It is said: وَتَمَّتْ كَلِمَتُ رَبِّكَ صِدْقًا وَعَدْلًا ۚ لَّا مُبَدِّلَ لِكَلِمَاتِهِ (And the Word of your Lord is perfect in truth and justice. None is there to change His Word).
The word: تَمَّتْ (tammat) denotes the state of perfection and: كَلِمَتُ رَبِّكَ (kalimatu Rabbik) refers to the Qur'an (A1-Bahr A1-Muhit, from Sayyidna Qatadah). All subjects of the Qur'an are of two kinds: (1) Those in which lesson-oriented events and conditions of world history, reward on good deeds and warning of punishment on evil deeds have been described; and (2) those in which injunctions relating to human betterment and prosperity have been laid out. It is about these two kinds that the following two qualities of the Qur'an have been identified: صِدْقًا وَعَدْلًا ، that is, perfect in truth and justice. Here, صِدْقً (sidq:truth) belongs to the first kind. It means that all events, conditions, promises or warnings mentioned in the Qur'an are true and correct. There is no possibility of fault or defect or error in them. And: عَدْلً (` adl: justice) relates to the other kind, that is, the injunctions (Ahkam). It means that all injunctions of Allah Jalla Sha'nuhu are based on ` Adl (justice). The sense of Adl covers two meanings: (1) Justice under which no injustice has been done to anyone, nor has any right been compromised or usurped; and (2) اعتدال I` tidal (moderation), that is, not being totally subordinated to the desires of human self, nor being what ingrained human emotions and natural traits cannot bear. This comes to mean that all Divine injunctions are based on justice and moderation, that is, in them, there is no injustice inflicted on anyone, nor do they have hardship and pain which are humanly unbearable - as said elsewhere: لَا يُكَلِّفُ اللَّـهُ نَفْسًا إِلَّا وُسْعَهَا (Allah does not obligate anyone except to his capacity - 2:286). Then, along with it, by bringing in the word: تَمَّتْ (tammat: is perfect), it was also pointed out that the Holy Qur'an not only has the qualities of truth and justice, but that it is also perfect and complete in them in all respects.
And that all injunctions of the Qur'an be - for all peoples of the world, for all generations to come and for all changed conditions - based on both justice and moderation is something which, if considered with a little deliberation, can only be possible in nothing but Divine injunctions. No legislative assembly or congress of the world can completely foresee all forthcoming conditions in the present and the future, nor can it make any law which would accommodate all such conditions. Every country and nation makes its laws keeping in view what are usually the prevailing conditions of that country or nation. Then, even those laws are made to undergo changes when their experience proves that many of their provisions have remained contrary to justice and moderation. Now, to make a master law for other nations and peoples, or to make it with a complete consideration of all future events - that which embodies in it the qualities of justice and moderation for every nation, every country and every condition - is something beyond human thought and perception. This can only be in the Word of Allah Subhanuhu wa Ta` ala. Therefore, this fifth quality of the Holy Qur'an, the quality of truth and justice, is impeccable. It demonstrates that all past and present events, promises and warnings, narrated in it are true, wherein the least doubt of their being contrary to the actual cannot be entertained, and that all injunctions given by it are embedded with justice and moderation for the benefit of the whole world for all generations to come right through the Last Day of Qiyamah, in-junctions which inflict no injustice on anyone, nor is there the slightest deviation from the norms of moderation and balance. This is, in itself, the perfect proof of the Qur'an being the Divine Word.
The sixth quality has been identified لَّا مُبَدِّلَ لِكَلِمَاتِهِ that is, there is no one who can change the words of Allah Ta` ala. One form in which such a change can take place is when someone proves a mistake in it because of which it has to be changed; or, that some enemy changes it forcibly. The Word of Allah is pristinely pure and far beyond any such possibilities. He has Himself promised: إِنَّا نَحْنُ نَزَّلْنَا الذِّكْرَ وَإِنَّا لَهُ لَحَافِظُونَ ﴿9﴾ that is, ` We (only We) have revealed the Dhikr (the Qur'an) and, for it, We (only We) are the Protector - 15:9). When so, who can dare break through the protection of Allah and make any changes or alterations in it? For that matter, over fourteen hundred years have passed and there have been, in every century and every age, more people who have been against it as compared in numbers, even in power, with those who have been believing it, but not one of them had the courage to introduce one tiny variance in even a vowel point of the Qur'an. Of course, possible there was a third form of bringing in a change, that is, it be changed through abrogation (naskh) by Allah Ta` ala Himself. Therefore, Sayyidna ` Abdullah ibn ` Abbas ؓ said: ` This verse indicates that the noble Prophet ﷺ is the Last Prophet and the Qur'an, the Last Book. After this, there is no probability of an abrogation' - as it has been elucidated in other verses of the Qur'an.
At the end of verse (115), it was said: وَهُوَ السَّمِيعُ الْعَلِيمُ (and He is All-Hearing, All-Knowing) which means that Allah Jalla Sha'nuhu hears all that is being said by these people and He knows what they do openly and secretly. He will give a return for every deed of theirs in accordance with it.