It is narrated from Sayyiduna Anas bin Malik (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) prescribed, for the treatment of 'irq al-nasa (sciatica), the fat tail of an Arab sheep, neither very small nor very large; it is melted, its fat divided into three parts, and then one part is drunk each day on an empty stomach. Anas (bin Sirin, the narrator) said: I have described this remedy to three hundred people, and Allah Almighty granted healing to all of them.