Muwatta Malik, Book 16, Hadith 571 (In-Book)

Yahya related to me from Malik from Abu'z Zinad from al-Araj from Abu Hurayra that the Messenger of Allah, may Allah bless him and grant him peace, said, "The earth eats all of the son of Adam except the coccyx. He was created from it, and on it he is built."

وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ أَبِي الزِّنَادِ، عَنِ الأَعْرَجِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏ "‏ كُلُّ ابْنِ آدَمَ تَأْكُلُهُ الأَرْضُ إِلاَّ عَجْبَ الذَّنَبِ مِنْهُ خُلِقَ وَفِيهِ يُرَكَّبُ ‏" ‏ ‏.‏

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also referenced under: Book 16, Hadith 49 (USC-MSA)