Muwatta Malik, Book 17, Hadith 56 (USC-MSA)

Yahya related to me from Malik from Nafi that Abdullah ibn Umar used to send the zakat al-fitr to the one with whom it was collected together two or three days before the day of breaking the fast.

حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنْ نَافِعٍ، أَنَّ عَبْدَ اللَّهِ بْنَ عُمَرَ، كَانَ يَبْعَثُ بِزَكَاةِ الْفِطْرِ إِلَى الَّذِي تُجْمَعُ عِنْدَهُ قَبْلَ الْفِطْرِ بِيَوْمَيْنِ أَوْ ثَلاَثَةٍ ‏.‏

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also referenced under: Book 17, Hadith 632 (In-Book)