Sayyiduna Abu Rafi' (may Allah be pleased with him) narrates: The Prophet (peace and blessings be upon him) sent Sayyiduna Umar (may Allah be pleased with him) to collect zakah. He came to Sayyiduna al-Abbas bin Abd al-Muttalib (may Allah be pleased with him), and Sayyiduna al-Abbas (may Allah be pleased with him) spoke harshly to him. Sayyiduna Umar (may Allah be pleased with him) came to the Prophet (peace and blessings be upon him) and mentioned this to him. The Prophet (peace and blessings be upon him) said: "O Umar! Do you not know that a man's paternal uncle is like his father? Al-Abbas had already given us this year's zakah (in advance) last year."
Al-Tabarani recorded it in al-Mu'jam al-Awsat. Its chain contains Isma'il al-Makki; he has been heavily criticised, and he has also been declared trustworthy.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الزكاة / 4423