Jami` at-Tirmidhi 3760
جامع الترمذي#3760SahihNarrated 'Ali:that concerning Al-'Abbas, the Prophet (ﷺ) said to 'Umar: "Indeed, the uncle of a man is the Sinw of his father." And 'Umar had spoken to him concerning his charity
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Ahmad Muhammad ShakirSahih Lighairihi
Al-AlbaniSahih
Zubair Ali ZaiSahih
In-book reference: 49:159