It is narrated by Hazrat Jabir رضی اللہ عنہ that Prophet ﷺ summoned Hazrat Ali رضی اللہ عنہ at the time of Ghazwa Taaif and whispered to him. The Companions of Prophet صلی اللہ علیہ وسلم asked that O Prophet صلی اللہ علیہ وسلم you have whispered to your cousin brother for a long time. So Prophet ﷺ said that not me alone but God has also whispered to him (Tarmiziz Abi Asim, Tarmizi said that it is the standardized Hadith)Hazrat Ali رضی اللہ عنہ said that I know about every verse of Quran that who it was about, at what place it came and on whom. . Undoubtedly My God has bestowed upon me a heart of very much wisdom and a very clear tongue for elaborating things. (Abu Naeem, Ibn E Saad)Hazrat Abu Ishaaq رضی اللہ عنہ narrates that Hazrat Abdullah رضی اللہ عنہ used to narrate that among the inhabitants of city of Madina Hazrat Ali رضی اللہ عنہ son of Abi Talib is the best decision maker. (Imam Hakim)
Hazrat son of Umer رضی اللہ عنہ states that Prophet صلی اللہ علیہ وسلم said that Hazrat Hassan and Husssain رضی اللہ عنہ are the leaders of youth of Heaven and their father is better than both of them. (Ibn e Maja)
