The book Biayatul Mujtahid contains one of them is about purification which means: In the book al-Fiqh al-Manhaji, it is stated that thaharah in language is al-Nadzafah, which is clean from visible and invisible dirt. While the meaning of thaharah according to syar'i is doing something that can allow prayer and other worship.

Fiqh scholars have great concern regarding this thaharah. In the books of fiqh, almost all of the first discussions start from this topic. Because thaharah is the first and main requirement in carrying out worship. An act of worship is not considered valid according to the Shari'a if the thaharah has not been fulfilled.