Syed Ibn Taoos writes in his book Mohijjud Dawaat - one of the blessed & magnificent books of Islam - that Ibn Abbas narrates that once when I went to meet Holy Prophet (s.a.w.a), I found him (s.a.w.a) happy and smiling. I asked him (s.a.w.a), 'May I be sacrificed for you! What is the (good) news that has made you happy?' Holy Prophet (s.a.w.a) replied, 'O Ibn Abbas! Jibraael came to me with a dua (supplication) which is a blessing for me and my nation. He (Jibraeel) said, "O Mohammed! Take this dua and read it and respect it for it is one of the treasures from the treasures of Paradise. Allah has honoured you and your nation by this dua."
Holy Prophet (s.a.w.a) asked, "O Jibraeel! Which dua is this?" Jibraeel - who is one of the proximate angels of Allah said - "It is one of the glorifications and venerations of Allah." Ibn Taoos narrates that firstly let us see the reward of recitation of this dua. Holy Prophet (s.a.w.a) asked Jibraeel, "O Jibraeel! What is the reward for the one who recites this dua?" Jibraeel replied, "O Mohammed! You have asked me about a reward which no one knows except Allah. If all the oceans were to become ink and all the trees were to be pens and all the angels were to become writers and if they would write for a duration equal to thousand times of the life of this earth, yet they will not be able to compute the reward of this dua. O Mohammed! I swear by the One who raised you as a prophet. Any man or woman who recites this dua will receive the reward of four messengers (a.s) and four angels. The four messengers are you (a.s), H. Isa (a.s), H. Moosa (a.s) and H. Ibrahim (a.s). And the four angels are me, Israfeel, Mikaeel and Izraael.
O Mohammed! Any man or woman who recites this dua twenty times in his or her lifetime, then Allah will not punish him with the fire of Hell. And He will forgive all their sins even if they are equal to the froth of the ocean or the drops of rain or the stars of the sky or the hair on the body or they are equal in weight to the Arsh, Kursi, Qalam, Lauh. Allah will erase all his sins and replace each sin with a thousand rewards. O Mohammed! If a person is engulfed in sorrow and calamities or is fearful of something, and he recites this dua thrice, then Allah will surely fulfil his wishes. If a person is afraid of a lion or a wolf or is going to meet a tyrant king, and if he recites this dua, then Allah - by His Power - will keep him safe from the evil of that king. Anyone who recites this dua before going for a battle, then Allah will give him the strength of seventy warriors. Anyone who recites this dua while he is having a headache or a stomach ache or pain in the eyes or is stung by a snake or scorpion then Allah will dispel all these problems. O Mohammed! Anyone who does not believe in this dua is not from Me. And the one who rejects this dua will be deprived of blessings."
Holy Prophet (s.a.w.a) asked, "O Jibraeel! Why is this dua superior to other duas?" Jibraeel replied "Because it contains 'Ism-e-Aazam.' Anyone who recites this dua, Allah will increase his memory,intelligence, age and bodily health. Allah will dispel from him seventy calamities of the world and seven hundred calamities of the hereafter." This completes the first tradition regarding the reward of this dua. We now go to the second tradition about the merits of this dua
Ameerul Momineen (a.s) narrates a tradition from Holy Prophet (s.a.w.a) about the excellence and reward of this dua.He (a.s) says that Holy Prophet (s.a.w.a) said, "Jibraeel (a.s) descended near me while I was praying near Maqam-e-Ibrahim and seeking forgiveness for my ummah. Jibraeel said, 'O Mohammed! You are too desirous for the forgiveness of your nation while Allah Himself is very Merciful!' Holy Prophet (s.a.w.a) told him, 'My brother Jibraeel. You are my friend and the friend of my nation. Teach me a supplication by which my nation will remember me.' Jibraeel said, 'O Mohammed! I do wasiyat to you that you instruct your nation that they should fast in the "AyyamBaiyz" (13th, 14th& 15th of every month). And I do wasiyat that you order your nation to recite this dua on all three days.
Know that the bearers of Arsh are holding the Arsh by the blessings of this dua; I descend to the earth and rise up to the heavens by the blessings of this dua. This dua is written on every door and every room of Paradise. Due to the blessings of this dua, all the doors of Paradise are unlocked and the person will be included in the clemency of Allah. Anyone from your nation who recites this dua will be saved from the chastisements of the grave and "Faz-e-Akbar" and will be protected from the troubles of the world and hereafter. And he will be saved from the fire of hell. Anyone who recites this dua and seeks his wishes from Allah, it will be certainly granted. The reciter of this dua will be safe from a sudden death and the fear of the grave and will be free from poverty. Allah will grant him the permission to intercede for others on the day of Qiyamat. Allah will cause him to enter Paradise - due the blessings of this dua - and will robe him in dresses of Paradise which will never become old. Anyone who recites this dua while he is fasting, then Allah will grant him the reward of Jibraeel, Mikaael, Israfeel, Izraeel, H. Ibrahim (a.s), H. Isa (a.s), H. Moosa (a.s) & Holy Prophet (s.a.w.a).
Then Holy Prophet (s.a.w.a) said, "I'm surprised at the enormous rewards of this dua.Jibraeel continued, "O Mohammed! There is none from your ummah who will recite this dua once in his entire life except that Allah will raise him in Mahshar while his face will be glowing like the full moon. The people will ask - "Who is this person? Is he a prophet?" The angels will reply, "He is neither a prophet nor an angel. Rather he is the son of Adam (i.e. a man). Allah has granted him this honour for the sake of this dua that he once recited in his life. O Mohammed! Anyone who recites this dua five times in his life, then I will be standing next to his grave on the day of Qiyamatand along with me will be "Boraaq" - a mount from Paradise. When this person will mount Boraaq, it will not stop except that it takes him to the abode of eternity. He will be exempted from all accounting. Anyone who is hungry or thirsty and is unable to find a thing to satiate his hunger or is ill and if he recites this dua, then Allah will provide him with food that he can eat. Anyone who fears his enemy must recite this dua. Allah will provide him with a formidable safety and the enemy will not be able to harm him. Anyone who is in debt recites this dua, then Allah will ensure that his debt is repaid or will provide him with a person who will repay his debt.
Anyone who believes in Allah prays this dua with sincerity on a mountain, the mountain will move from its place. And anyone recites this dua on (flowing) water, the water will freeze immediately. Don't be amazed by the merits of this dua for it contains "Ism-e-Aazam". When a person recites this dua, then all the angels and jinn who hear this dua, pray for that person and Allah accept their prayers. Anyone who believes in Allah and His Prophet (s.a.w.a) should not have any doubt concerning the merits that have been mentioned about this dua for Allah can grant beyond expectations and imaginations. Anyone who knows about this dua must not be miser in introducing it to other Muslims."
Then Holy Prophet (s.a.w.a) continued and said, "I have never participated in any battle without reciting this dua and I have always been victorious over my enemies due to the blessings of this dua. Any person who recites this dua is blessed with the light of the Awliya of Allah on his visage. All his difficulties will be solved and he will find a way out from all calamities. Anyone who listens to this dua out of respect, then Allah will protect him from all difficulties and save him from all evil strategies of the enemies..
wa subhaanahu min qadeerim ma-akhzamahu wa subhaanahu min a'zeemin maa-ajallahu wa subhaanau min jaleelim maa amjadahu
Glory be to He in (His) omnipotence! How powerful He is! Glory be to He in (His) power! How mighty He is! Glory be to He in (His) might! How eminent He is
wa subhaanahu howallaahul a'zeemo wa be hamdehi wal hamdo lillaahe wa laa elaaha illal laaho wal laaho akbar,
Glory be to He! He is Allah the Supreme and (all) praise be to Him.And (all) praise be to Allah. There is no god except Allah, and Allah is Great and for Allah is Praise.