(Purifying Belief from Atheism’s Defilement (Third Edition) is a manuscript on the science of belief. It was written by Al-San’ani Muhammad bin Ismail bin Salah, who died in 1182 AH. It was copied by Ali bin Saad bin Nafisa bin Ahmed bin Ali in 1282 AH in the Naskh script, and the number of sheets was 18 sheets, and the number of lines 18, size 23 x 16 cm, in a total from P. 1 to P. 35. The first endowment is for Munira bint Mashari at the hands of her son, Muhammad bin Faisal, and Hussein bin Nafisa. This certificate was written and stamped by Abdul Aziz bin Saleh bin Murshid on 1286 AH. It is identical to its original and corrected. Black ink was used in writing and red was used for what is to be distinguished, and it was bound locally from cardboard covered with red leather and decorated with pressed decorations.