Imam Reza (as) - Dua

He taught the following holy supplication to his companion and student, Mūsā b. Bukayr. He said to him: “Memorize what I write to you. Supplicate with it during every hardship of which you are afraid.” The supplication is as follows: “In the Name of Allah, the Most Gracious, the Most Merciful. O Allah, my many sins have made me lose face before You, prevented me from being worthy of Your mercy, and kept me away from deserving Your forgiveness! I have adhered to Your boons and  clung to supplicating You, for You have promised those who are like me in acting extravagantly (against their own souls), making errors, and despairing of Your mercy through Your words:  Say: O My servants who have acted extravagantly against their own souls, do not despair of the mercy of Allah; surly Allah forgives the faults altogether; surely He is the Forgiving, the Merciful. You have warned those who despair of Your mercy and said: And who despairs of the mercy of his Lord but the erring ones. Then You have summoned us through Your mercy to supplicate You, thus You have said: Call upon me, I will answer you; surely those who are too proud for My mercy shall soon enter hell abased.
“O my Lord, hopelessness has covered me, and despair of Your mercy has wrapped me! O my Lord, You have promised to reward him who has good opinion in You and to punish him who has bad opinion in You! O Allah, my eye has been seized by good opinion of You in releasing my neck from the Fire, covering my slips, releasing (me) from my stumble! O Allah, Your words, which have neither alteration nor change, are true: (Remember) the day when We will call every people with their Imām.[1] That is the Day of Resurrection when the trumpet shall be blown and what is in the graves shall be raised. I believe, witness, confess, do not deny, do not renege, conceal, announce, manifest, and hide that You are Allah, there is no god but You, One with no partner with You, that Mohammed is Your servant and messenger, may Allah bless him and his Family, and that ‘Ali, the Commander of the faithful, master of the testamentary trustees, inheritor of knowledge of the prophets, emblem of religion, destroyer of the hypocrites, the fighter against the Renegades (Māriqin), my Imām, my proof, my handle, my path, my guide, and my argument. I do not trust my deeds though pure; nor do I see that they will save me though righteous but through (showing) friendship to him, following his example, acknowledging his great virtues, accepting from those who delivered them, and submitting to those who narrated them. I confess that his testamentary trustees from among his grandsons are Imāms, arguments, guides, lamps, guideposts, lighthouses, masters, and pious. I believe in their secret, their openness, their outward, their inward, their present, their absent, their living, and their dead. In that there is neither doubt nor suspicion nor change when You turn away (from that).
“O Allah, summon me on the day of my mustering and my resurrecting through their Imāmate, and save me, O My Protector, from the heat of the Fires through them, and supply me with the repose of the Gardens! Surely, if You release me from the Fire, I will be one of the achievers. O Allah, I rose in the morning of this day of mine (while) I have neither confidence nor hope nor asylum nor place of flight nor shelter except those through whom I seek access to You, seeking nearness to Your Messenger Mohammed, may Allah bless him and his Family, then ‘Ali, the Commander of the faithful, al-Zahrā’, the mistress of the women of the worlds, al-Hasan, al-Husayn, and the one after them who will pave the way for the hidden proof from among his children, hoped for the community after him.
“O Allah, make them in this day and after it my fortress against detested things and my stronghold against fears; save me through them from every enemy, tyrant, oppressor, sinner, the evil of what I know, what I deny, what has hidden from me, what I see, and the evil of every crawling creature that You have taken by the forelock! Surely You are on a straight path.
“O Allah, through my seeking access through them to You, seeking nearness to You through showing love for them, fortifying myself with their Imāmate, open for me the doors to Your provision; spread upon me Your mercy; make Your creatures love me; turn me aside from their detest and their enmity! Verily You are powerful over everything.
“O Allah, there is reward for everyone (who) seek access (through them to You); there is right for all the possessors of intercession, hence by him whom You have appointed as Your friend and placed ahead my request, I ask You to make me recognize the blessing of this day of mine, this month of mine, and this year of mine!
“O Allah, they are my place of flight and my help during my hardship, my ease, my well-being, my tribulation, my sleep, my wakefulness, my departure, my residence, my difficulty, my facility, my openness, my secret, my morning, my evening, my movement, my habitation, my secret, and my publicity! O Allah, through them, disappoint me not of Your favor; cut not my hope from Your mercy; disappoint me not of Your repose; tempt me not with the closure of the doors to provisions and of the ways to them; open for me an easy opening from You; appoint for me a way out from every hardship and a road for every plenty! Surely, You are the Most Merciful of the merciful. May Allah bless Mohammed and his pure Household! Amen, Lord of the world! ( Muhajj al-Da'awāt, pp. 315-317. )

Reference :The life of Imām'Ali Bin Mūsā al-Ridā