Musnad Ishaq

Benefits:
It is understood that the Greatest Name (Ism al-A’zam) of Allah, the Lord of Majesty, possesses immense virtue. As narrated from Qasim bin Abdur Rahman Dimashqi rahimahullah, he said: The Greatest Name (Ism al-A’zam) of Allah, with which if one supplicates to Allah, the Lord of Majesty, He answers, is found in three surahs: Surah al-Baqarah, Surah Aal-e-Imran, and Surah Taha. (Sunan Ibn Majah, No. 3856)

However, through another chain, this is also established as a marfu’ narration from the Noble Prophet sallallahu alayhi wa sallam. As narrated from Sayyiduna Abu Umamah radi Allahu anhu, the Noble Prophet sallallahu alayhi wa sallam said: “The Greatest Name (Ism al-A’zam) of Allah, the Exalted, is in these three surahs of the Noble Qur’an: Surah al-Baqarah, Aal-e-Imran, and Surah Taha.” (Silsilat al-Sahihah, No. 746)

Shaykh al-Albani rahimahullah says that the Ism al-A’zam is in the beginning of Surah Taha: ﴿إِنَّنِي أَنَا اللَّهُ لَا إِلَٰهَ إِلَّا أَنَا﴾ (“Indeed, I am Allah; there is no deity except Me”). (Silsilat al-Sahihah, commentary on hadith no. 746)

Hafiz Ibn Hajar Asqalani rahimahullah has presented fourteen opinions regarding the identification of the Ism al-A’zam:
(1) هُوَ (He)
(2) اَللّٰهُ (Allah)
(3) اَللّٰهُ الرَّحْمٰنُ الرَّحِیْمِ (Allah, the Most Merciful, the Most Compassionate)
(4) اَلرَّحْمٰنُ الرَّحِیْمُ اَلْحَیُّ الْقَیُّوْمُ (The Most Merciful, the Most Compassionate, the Ever-Living, the Sustainer)
(5) اَلْحَیُّ الْقَیُّوْم (The Ever-Living, the Sustainer)
(6) اَلْحَنَّانُ اَلْمَنَّانُ بَدِیْعُ السَّمَوَاتِ وَالْاَرْضِ ذُوْالْجَلَالِ وَالْاِکْرَامِ اَلْحَیُّ الْقَیُّوْمُ (The Most Compassionate, the Bestower, the Originator of the heavens and the earth, the Lord of Majesty and Honor, the Ever-Living, the Sustainer)
(7) بَدِیْعُ السَّمَوَاتِ وَالْاَرْضِ ذُوْالْجَلَالِ والْاِکْرَامِ (The Originator of the heavens and the earth, the Lord of Majesty and Honor)
(8) ذُوْالْجَلَالِ وَالْاِکْرَامِ (The Lord of Majesty and Honor)
(9) اَللّٰهُ لَا اِلٰهَ اِلَّا هُوَ الْاَحَدُ الصَّمَدُ الَّذِیْ لَمْ یَلِدْ وَلَمْ یُوْلَدْ وَلَمْ یَکُنْ لَّهٗ کُفُوًا اَحَدٌ (Allah, there is no deity except Him, the One, the Self-Sufficient, who neither begets nor is born, and there is none comparable to Him)
(10) رَبِّ رَبِّ مَا اسْمُ اللّٰهِ الْاَکْبَرُ رَبِّ رَبِّ (My Lord, my Lord, what is the Greatest Name of Allah? My Lord, my Lord)
(11) لَا اِلٰهَ اِلَّا اَنْتَ سُبْحَانَكَ اِنِّیْ کُنْتُ مِنَ الظَّالِمِیْنَ (There is no deity except You; Glory be to You! Indeed, I was among the wrongdoers)
(12) هُوَ اللّٰهُ اَّلِذْی لَا اِلٰهَ اِلَّا هُوَ رَبُّ الْعَرْشِ الْعَظِیْمِ (He is Allah, there is no deity except Him, the Lord of the Mighty Throne)
(13) هُوَ مَخْفِیٌّ فِی الْاَسْمَاءِ الْحُسْنٰی (It is hidden among the Most Beautiful Names)
(14) کَلِمَةُ التَّوْحِیْدِ (The statement of Tawhid [monotheism])

(Fath al-Bari: 11/268, 269, Hadith: 6410, Maktabah Qadimi, Karachi)