As for al-Hafiz’s attribution of it in Fath al-Bari (8/514) to Ibn Hibban and al-Hakim, I can only regard it as an error. Al-Haythami said in al-Majmaʿ (7/89): “It was narrated by Ahmad and al-Bazzar, and the narrators in Ahmad’s chain are narrators of the Sahih collections.”
The hadith has an authentic corroborating report narrated by Abu Hurayrah, may Allah be pleased with him, in the account of Gabriel’s coming and his questions concerning faith, Islam, spiritual excellence, and the Hour. It was recorded by al-Bukhari and Muslim, Ibn Hibban (1/188/159), and others, and is cited in Irwaʾ al-Ghalil (1/32/3).
There is another corroborating report from Abd Allah ibn Umar, with the wording: “The keys to the unseen are five...” the hadith. It was recorded by al-Bukhari (1039), Ibn Hibban (1/144/70 and 7/647/6101), and Ahmad (2/24, 52, and 58), through Abd Allah ibn Dinar from him. Salim ibn Abd Allah also narrated it from Abd Allah with the same wording. Ahmad recorded it (2/122). Its chain of transmission is authentic according to the criteria of al-Bukhari and Muslim.
Al-Haythami included this hadith of Ibn Umar in Mawarid al-Zamʾan ila Zawaʾid Ibn Hibban (434/1754 and 1755), although it does not meet the criterion of that work, as you can see.
Note: The authentic chain of transmission for the hadith under discussion—as attested by those leading hadith authorities, al-Diyaʾ al-Maqdisi, al-Suyuti, and likewise Ibn Kathir—is a clear and powerful refutation of that pseudo-scholar who wreaked havoc upon al-Nawawi’s Riyad al-Salihin, altering and tampering with it. He removed dozens of authentic hadiths from it, alleging that they were weak, and appended them to his edition of Riyad, clinging to justifications flimsier than a spider’s web. Among this is his declaring weak (p. 560) two authentic hadiths likewise narrated by Ahmad from Abd Allah ibn Buraydah, from his father, on the claim that