Abu Hurairah and Kaab met together. Abu Hurairah began narrating to Kaab from the Prophet ﷺ, while Kaab narrated to Abu Hurairah from the scriptures.Abu Hurairah said, the Prophet ﷺ said, "Every prophet has a supplication that is answered, and I have reserved my supplication as intercession for my community on the Day of Resurrection."
حدثنا عبد الرزاق حدثنا معمر عن الزهري قال
اجتمع أبو هريرة وكعب فجعل أبو هريرة يحدث كعبا عن النبي ﷺ وكعب يحدث أبا هريرة عن الكتب قال أبو هريرة قال النبي ﷺ لكل نبي دعوة مستجابة وإني اختبأت دعوتي شفاعة لأمتي يوم القيامة
Its chain is sahih. Muslim (1:750) also narrated it from Zuhri, from Amr bin Abu Sufyan bin Usayd bin Jariya Thaqafi, with similar wording, that Abu Hurairah mentioned the marfu hadith to Kaab Ahbar, and Kaab said to Abu Hurairah, "Did you hear this yourself from the Messenger of Allah ﷺ?" Abu Hurairah said, "Yes." Kaab Ahbar has no role in the transmission of this hadith except that he heard it from Abu Hurairah. See what we quoted from Khattabi regarding Kaab Ahbar in the commentary on hadith 1416.The meaning of the marfu hadith is established from Abu Hurairah, as marfu, through more than one route. Malik narrated it in Muwatta (p. 212) from Abu Zinad, from Araj, from Abu Hurairah, and it will come in the Musnad at 10316, by way of Malik. Bukhari likewise narrated it (11:81) by way of Malik.Zuhri also narrated it from Abu Salama bin Abdul-Rahman, from Abu Hurairah. It will come at 8946, from the narration of Maamar, and at 9132, from the narration of Abu Uways, both from Zuhri, from Abu Salama. Bukhari likewise narrated it (13:378) by way of Shuayb, and Muslim (1:75) by way of Malik, and by way of the son of Zuhri's brother. Khatib also narrated it in Tarikh Baghdad (11:141) by way of Shuayb, all of them from Zuhri, from Abu Salama.Amash also narrated it from Abu Salih, from Abu Hurairah. It will come in the Musnad at 9500, by way of Amash. Ibn Majah likewise narrated it (4307), and Khatib in Tarikh Baghdad (2:424), both from the narration of Amash, from Abu Salih.Muhammad bin Ziyad also narrated it from Abu Hurairah. It will come in the Musnad at 9292 and 9548, from the narration of Shuba, from Muhammad bin Ziyad. Muslim likewise narrated it (1:75) by way of Shuba.Hammam bin Munabbih also narrated it from Abu Hurairah, and it will come in the Musnad, in the collection of Hammam bin Munabbih, at 8117, from the narration of Maamar, from Hammam bin Munabbih.Abu Zura bin Amr bin Jareer also narrated it from Abu Hurairah. Muslim narrated it (1:75), from the narration of Ammar bin Qaqa, from Abu Zura.The Hafiz has explained it fully in al-Fath (11:81–82). Its meaning has already occurred within a longer hadith from Ibn Abbas (2546, 2692), and within another hadith from Abdullah bin Amr bin As (7068).