Expiation, Their Obligations And Provisions In Islamic Law - A Comparative Jurisprudential Study PHD (Doctor of Philosophy) thesis by researcher: Ismail bin Abdullah Al-Wazzaf. This thesis was supervised by Professor Dr. Abdul Karim Zidan, and it was discussed in Republic of Yemen/ Sana’a University/ College of Arts/ Department of Islamic Studies in the year 1420 AH / 2000 AD to obtain a PHD degree in Islamic Studies.