Narrated '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. (FR)
English reference (FR): Vol. 1, Book 46, Hadith 3760 (FR)
Arabic reference (FR): Book 49, Hadith 4127 (FR)