Muwatta Malik, Book 20, Hadith 845 (In-Book)

Yahya related to me from Malik from Yahya ibn Said that Umar ibn Abd al-Aziz once sacrificed a camel during a hajj or an umra.

وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ يَحْيَى بْنِ سَعِيدٍ، أَنَّ عُمَرَ بْنَ عَبْدِ الْعَزِيزِ، أَهْدَى جَمَلاً فِي حَجٍّ أَوْ عُمْرَةٍ ‏.‏

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also referenced under: Book 20, Hadith 142 (USC-MSA)