All perfect praise be to Allah the Lord of the Worlds. May His peace and blessings be upon our Prophet Mohammad and upon all his family and companions.
Supplicating and seeking intercession through the verses of the Qur'an or through prophets and righteous people is a permissible act. It is narrated by 'Uthman ibn Hunaif from Abu Umamah ibn Sahl ibn Hunayf from his uncle that a blind man came to the Prophet (peace and blessings be upon him) and said: "O Messenger of Allah, pray to Allah to restore my sight." The Prophet (peace and blessings be upon him) said: "Shall I not leave it (as it is for you)?" He said: "O Messenger of Allah, it is hard for me to be without my sight." The Prophet (peace and blessings be upon him) said: "Go and perform ablution, then pray two rak'ahs, then say: 'O Allah, I ask You and turn to You by Your Prophet Muhammad, the Prophet of mercy. O Muhammad, I turn to my Lord through you, that He should fulfill my need. O Allah, accept his intercession for me and accept my intercession for myself.'" The man then returned, and Allah had restored his sight. [Al-Sunan Al-Kubra by Al-Nasa'I, Vol. 9/P. 245].
A believer can supplicate for whatever they desire regarding matters of this world and the Hereafter. This is based on Allah's statement {which means): {And when My servants ask you concerning Me, indeed I am near. I respond to the invocation of the supplicant when he calls upon Me} [Al-Baqarah: 186], and Allah's statement (which means): {And your Lord says, "Call upon Me; I will respond to you." Indeed, those who disdain My worship will enter Hell contemptible} [Ghafir: 60].
Scholars have unanimously agreed on the permissibility of supplicating with the established supplications (du'as) from the Quran and the Sunnah. The jurists of the Shafi'i school have also permitted supplicating with non-established supplications. Imam Nawawi, may Allah have mercy on him, said: "Al-Shafi'i and his fellow scholars said: It is permissible for him [the person] to supplicate for whatever he wishes regarding matters of the Hereafter and the world. However, matters of the Hereafter are superior. He may supplicate with the established supplications in this context [meaning in prayer], those established in other contexts, and he may supplicate with non-established supplications, and with whatever he desires of matters pertaining to the Hereafter and the world." [Al-Majmu' Sharh al-Muhadhab, Vol. 3/P. 469].
As for supplicating with the disjointed letters found at the beginnings of some chapters in the Quran, it is known that these letters are part of the verses of the Quran. According to Islamic law, supplicating to Allah using the Quran or any of its verses is permissible.
In the authenticated narrations, it is reported that the Prophet Muhammad (peace be upon him) advised using "حم" (Ha-Mim) as a slogan when encountering the enemy. This is recorded in hadith collections such as Ibn Abi Shaybah, Al-Nasa'i, Al-Hakim, and Ibn Mardawayh, narrated from Bara' bin Azib (may Allah be pleased with him). The Prophet (peace be upon him) said: "You will meet your enemy tomorrow, so let your slogan be {حم}, they will not be victorious."
In his book "Al-Dala'il," Abu Nu'aim narrated from Anas (may Allah be pleased with him) that after the Muslims were defeated at the Battle of Khaybar, the Prophet Muhammad (peace be upon him) took a handful of soil, threw it towards their faces, and said: "{حم} لَا ينْصرُونَ" ("Ha-Mim, they will not be victorious"). As a result, the enemy was defeated without the Muslims needing to shoot an arrow or stab with a spear.
Al-Baghawi and Al-Tabarani narrated from Shaibah ibn 'Uthman (may Allah be pleased with him) that on the day of Khaybar, the Prophet Muhammad (peace be upon him) took some pebbles, blew into them, and threw them towards the faces of the enemy, saying: "(شَاهَت الْوُجُوه {حم} لَا ينْصرُونَ)" ("Faces are defeated, Ha-Mim, they will not be victorious").
In the narration from Al-Muhallab ibn Abi Sufrah, who reported hearing the Prophet Muhammad (peace be upon him) say, "If the enemy camps near you, say: Ha-Mim, they will not be victorious"), which was narrated by Imam At-Tirmidhi, indicates the permissibility of supplicating with these specific Quranic letters during times of facing adversaries.
The scholars of hadith commentary explain that when the Prophet (peace be upon him) instructed to use "(حم لا ينصرون)" in the form of the passive voice, it signifies a declaration rather than a supplication. Al-Qadi (a scholar) mentioned that it denotes the virtue of the Surahs that begin with "Ha-Mim" and their elevated status from Allah, indicating "they will not be victorious." Al-Khattabi explained it as a statement of fact. If it were meant as a supplication, it would have been in the grammatical form of a supplication (majzum), indicating "they will not be helped." Ibn Abbas also reportedly said that "Ha-Mim" is one of the names of Allah, implying an oath by Allah that "they will not be victorious." Al-Jazari concluded that it means "O Allah, do not grant them victory," intending it as a statement rather than a supplication, as if saying: "By Allah, they will not be helped." [Tohfat al-Ahwathi, Vol.5/P.26].
The name "كهيعص" (Kaf Ha Ya 'Ayn Sad) from Surah Maryam (19:1) is mentioned by some companions of the Prophet (peace be upon him) as among the names of Allah. Al-Hakim in his book "Al-Mustadrak" narrates from Ibn Abbas (may Allah be pleased with him) that he interpreted these letters as follows: "Kaf from Karim (Generous), Ha from Hadi (Guide), Ya from Hakim (Wise), 'Ayn from 'Alim (All-Knowing), and Sad from Sadiq (Truthful)." Al-Hakim authenticated the hadith's chain of narration as sound, and Al-Dhahabi confirmed its authenticity.
Imam al-Bayhaqi in his book "Al-Asma' Wa al-Sifat" (The Names and Attributes) (Vol.1/P.230) mentions that the disconnected letters in the Quran are among the names of Allah. Ibn Abbas is reported to have said regarding Allah's statement in Surah Maryam (19:1), and similar verses starting with disconnected letters such as Ta-Ha, Ta-Sin, Ta-Sin-Mim, Ya-Sin, Saad, Ha-Mim, 'Ayn-Seen-Qaf, and others: these are oaths that Allah has sworn by, and they are among the names of Allah, the Mighty and Majestic.
These letters are the foundations of the beautiful names of Allah and His attributes. Imam al-Sijistani al-Shafi'i, may Allah have mercy on him, said: "Alif-Lam-Mim and other alphabetical letters at the beginning of surahs, some interpreters consider them as names of the surahs, identifying each surah by what it starts with. Some consider them as oaths, sworn by Allah the Almighty due to their honor and virtue, as they are the initials of His revealed books, and the foundations of His beautiful names and high attributes. Some consider them as letters derived from the attributes of Allah the Almighty, as Ibn Abbas, may Allah be pleased with him, said about 'Kaf-Ha-Ya-Ayn-Sad': The 'Kaf' is from 'Kaf,' the 'Ha' from 'Had,' the 'Ya' from 'Hakim,' the 'Ayn' from 'Alim,' and the 'Sad' from 'Sadiq'" [Gharib al-Qur'an, p. 45].
These are letters with meanings, as Imam al-Zarkashi al-Shafi'i, may Allah have mercy on him, mentioned in [al-Burhan fi 'Ulum al-Qur'an, Vol. 1/P.167], saying: "They appear in the Qur'an in twenty-nine surahs, and without repetition, they total fourteen letters, which can be combined in the phrase: "Nas Hakim Qati`Laho Sir."
In conclusion, supplicating with these letters, or supplicating with one or more verses from the Qur'an, based on what is mentioned in the Sunnah of the Prophet, is permissible and not considered an innovation. This is because these letters are from the Qur'an, which is the eternal speech of Allah and one of His attributes. We can also add that the door of supplication is vast. And Allah The Almighty Knows Best.