Muwatta Malik, Book 16, Hadith 566 (In-Book)

Yahya related to me from Malik that Abu'r-Rijal Muhammad ibn Abd ar-Rahman heard his mother Amra bint Abd ar-Rahman say, "The Messenger of Allah, may Allah bless him and grant him peace, cursed both men and women who dug up," meaning those who dug up graves.

حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنْ أَبِي الرِّجَالِ، مُحَمَّدِ بْنِ عَبْدِ الرَّحْمَنِ عَنْ أُمِّهِ، عَمْرَةَ بِنْتِ عَبْدِ الرَّحْمَنِ أَنَّهُ سَمِعَهَا تَقُولُ، لَعَنَ رَسُولُ اللَّهِ صلى الله عليه وسلم الْمُخْتَفِيَ وَالْمُخْتَفِيَةَ يَعْنِي نَبَّاشَ الْقُبُورِ ‏.‏

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also referenced under: Book 16, Hadith 44 (USC-MSA)