What is Salat-i Nariya recited for?

I request someone to expand on the following with reference to "why salat-i-nariya" is recited: State of the need should be remembered while reciting it. The author cautioned with two verses from the holy Quran (42:49-50) that such a limitation as imposed by Allah should be considered by a person reciting this, even if s/he remembers her/his needs. However, it is known that it is only through recitation of salawat that predestined fates can be changed. Is that right? Please do highlight on this. Was salam.

Dua (prayer) is a kind of worshipping. Man gains the reward of worshipping through prayer no matter if a change takes place or not. - Since we do not know ghaib (the unknown, the unseen), we cannot know what is in our qadar (destiny). Therefore, what we need to do is to ask for our requests from Allah through prayer. - Allah knows what man will do through His pre-eternal knowledge. He says, “My servant will pray me and asks this and that and I will give them to him”; He determines our qadar accordingly. - I wonder if prayer can affect qadar. Can we change our qadar through our prayer? Qadar is the decision made about something. The carrying out of that decision is qada. To annul that decision and by skipping the carrying out of that judgment is ata (forgiving, grant). A soft grass can pierce a stone with hard grains; similarly, ata pierces the certainty of the law of qada. And qada pierces the decisions of qadar like an arrow. That is, the relation of ata to qada is like the relation of qada to qadar. Ata is an exception to the scope of the law of qada. And qada is an exception to the generality of the law qadar. A saint who is aware of this fact says, "O my Lord! My good deeds are out of your ata. My bad deeds are out of your qada. Were it not for your ata, I would be destroyed." (Mesnevi-i Nuriye, 206) That is, ata is defined as the annulment of the decision given about something and skipping the carrying out of that judgment. When ata is mentioned, the pardon and grant of ar-Rahim (the All Compassionate), al-Karim (the Generous), al Ghafur (the Forgiver) is understood. For instance, a certain misfortune was preordained in our qadar at a certain date; if that misfortune takes place at that date, it is called qada. However, a good deed of us or a prayer before that date may annul the judgment of that qada; the annulment of that judgment by Allah is called ata. We can explain the annulment of the law of qada by ata and the annulment of qadar by ata as follows: A king has general laws and the law of pardon and ata that he applies on certain dates. The king forgives some of the criminals on that day and alleviates the punishments of others; he promotes some of his officers and increases their salaries. The punishments, promotions and salaries that have been imposed by the general law are annulled by that law of ata. Suppose that a criminal was given an imprisonment of ten years for a certain crime that he committed. If that punishment is forgiven by the law of ata, the punishment is not carried out and the law of qada is changed. Since the punishment is not carried out, the law of qadar is changed; that is, the punishment given to him for his crime is annulled. As it is seen in the example above, the otherworldly punishments ordained by God Almighty for the sins that people commit are pardoned by His law of ata; that is, due to His pardoning and grant, qada is annulled; thus, the law of ata annuls the law of qada. Similarly, with the annulment of qada, the law of qadar is also annulled and the punishment that has been imposed is changed. Let us give another example: a slave leaves home with the intention and inclination of going to a place of sins. Since the slave pushes the button of will, Allah will create the result of his inclination and took him to the place where willed. However, a nice state of that person, for instance, the tears he sheds in the middle of the night, or driving one or two friends to a religious talk, may stir the Divine Mercy; Allah sends him a friend who will take him to a nice place not to a place of sin; thus, He changes the judgment due to the will of that person. That Allah changes a decree or a qada about a person with or without any reason is an ata belonging to Him. On the other hand, it is stated that ata is an exception to the scope of the law of qada. It can be explained as follows: the punishment imposed for a sin originates from a general law. That is, the decree stating that a person who commits a certain crime is given a certain punishment is a general law. If that person who commits that crime repents and if his sins are forgiven an exception to the scope of the law takes place. It also means an exception to the generality of the law qadar. The rule we have tried to explain above brings to the mind the question whether qadar changes or not. We should state that it is impossible for the Divine Knowledge to change. All of the events that took place and that will take place, including the application of the law of ata, are included in that knowledge. That qadar does not change. The changes take place in Lawh al-Mahw wa Ithbat (the Tablet of Erasure and Confirmation), which is a changeable board of the fixed and deep Lawh al-Mahfuz (the Preserved Tablet) in the scope of possibility. Many punishments that are preordained are forgiven through repentance and the law of ata; and they are erased from Lawh al-Mahw wa Ithbat. As a matter of fact, the following is stated in a verse in the Quran: Allah doth blot out or confirm what He pleaseth: with Him is the Mother of the Book. (ar-Ra'd, 39) How does a prayer change the fate? Our beloved Prophet Muhammad says the following: “Only prayer changes the fate. Only good deeds prolong one’s life. A person is deprived of sustenance only because of having committed sins.” In another hadith, the same subject is explained as follows: “Being cautious and carefulness does not affect the final decision of Allah. However, the prayer affects the calamities that were sent and not sent. A calamity is sent but the prayer prevents it and continues to resist it till the Doomsday.”1 Changing the course of the fate by prayer is explained as follows: Here what changes is not the fate (Qadar), but the Qada. Fate (Qadar) is the decision given for something and Qada is the execution of it. That is to say, a man prays sincerely, Almighty Allah rewards that man by eliminating a possible calamity that may happen to him. Here what changes is not the Fate (Qadar), but the cancellation of the Fate (Qadar) without being executed.