Muslim culture centred around the study and interpretation of the Koran and the sayings and deeds of Mohammed gathered together and passed on orally. The fuqaha (experts in Islamic law) and the ulema (the learned of Islam) played an extremely important role in regulating jurisprudence, passing on knowledge and traditions, and in stimulating the sciences and the arts. Ath-Thagr al-alaa was the land of origin of many wise men who learned, taught, travelled and held various posts around the Islamic world. The Christian and Jewish communities formed their own cultural focal points.