Mustadrak al-Hakim — Hadith 2021

Amr bin Shu'ayb narrates from his father, and he from his grandfather (Sayyiduna Abdullah bin Amr (may Allah be pleased with them both)), that Jibril (peace be upon him) descended from the heaven to the Prophet (peace and blessings be upon him) with this supplication. Jibril (peace be upon him) came to the Messenger of Allah (peace and blessings be upon him) in the most beautiful form he had ever come in, laughing and bearing glad tidings, and said: Peace be upon you, O Muhammad. He (peace and blessings be upon him) said: "And upon you be peace, O Jibril." He said: Allah Almighty has sent me to you with a gift. He (peace and blessings be upon him) asked: "O Jibril, what is that gift?" He said: It is some words from the treasures of the Throne, by which Allah has honoured you. He (peace and blessings be upon him) asked: "What are they, O Jibril?" Jibril (peace be upon him) said: Say: 'Ya man azhara al-jamil, wa satara al-qabih, ya man la yu'akhidhu bil-jarirah, wa la yahtiku al-sitr, ya 'azim al-'afw, ya hasan al-tajawuz, ya wasi' al-maghfirah, ya basit al-yadayn bil-rahmah, ya sahiba kulli najwa, wa ya muntaha kulli shakwa, ya karim al-safh, ya 'azim al-mann, ya mubtadi'a al-ni'am qabla istihqaqiha, ya Rabbana wa ya Sayyidana wa ya Mawlana, wa ya ghayata raghbatina, as'aluka ya Allahu an la tashwiya khalqi bil-nar' (O You who made the beautiful manifest and concealed the ugly; O You who does not (immediately) seize for a sin and does not tear away the veil; O Great in pardon; O Excellent in overlooking; O Vast in forgiveness; O You who spreads out both hands with mercy; O Companion of every secret conversation, and O final Refuge of every complaint; O Generous in overlooking faults; O Great in favour; O Initiator of blessings before they are deserved; O our Lord, O our Master, O our Protector, and O Utmost of our longing; O Allah, I ask You not to burn my being in the Fire). Then the Messenger of Allah (peace and blessings be upon him) asked: "What is the reward for these words?" After that he mentioned the long hadith that follows the supplication.
This hadith has a sahih (authentic) chain, because all its narrators are Madinans and trustworthy (thiqah), and I have previously mentioned the disagreement among the imams of hadith concerning whether Shu'ayb bin Muhammad heard from his grandfather.