Muwatta Malik 1568

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 ‏.‏

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

Reference

Muwatta Malik 1568

In-book

Book 43, Hadith 17