Hadith 8:121
Abu Bakr narrated to us, he said: Abd al-A’la narrated to us, from Hisham, from al-Hasan and ‘Ata’, who said: If his fingernail breaks, he should trim it from where it broke, and there is nothing upon him. If he trimmed it before it broke, then there is blood (a penalty) upon him.
حدثنا أبو بكر قال ثنا عبد الأعلى عن هشام عن الحسن وعطاء قال إذا انكسر ظفره قلمه من حيث انكسر وليس عليه شيء فإن قلمه من قبل أن انكسر فعليه دم