Muwatta Malik, Book 43, Hadith 1571 (In-Book)

Yahya related to me from Malik from Yahya ibn Said, that Said ibn al-Musayyab said, "For every piercing wound in any of the organs or limbs of the body, one third of the blood-money of that limb is payable."

وَحَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنْ يَحْيَى بْنِ سَعِيدٍ، عَنْ سَعِيدِ بْنِ الْمُسَيَّبِ، أَنَّهُ قَالَ كُلُّ نَافِذَةٍ فِي عُضْوٍ مِنَ الأَعْضَاءِ فَفِيهَا ثُلُثُ عَقْلِ ذَلِكَ الْعُضْوِ ‏.‏

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also referenced under: Book 43, Hadith 6 (USC-MSA)