Yahya related to me from Malik from Ibn Shihab that Said ibn al-Musayyab used to say, "The full blood-money is payable for cutting offboth lips, but when the lower one only is cut off, two-thirds of theblood-money is due for it."
USC-MSA web (English) reference: Book 43, Hadith 6
Arabic reference: Book 43, Hadith 1567