Of several non-obligatory things that can come to the aid of a momin is to always maintain the state of wadu. The Prophet of Islam (a.s.) says," Al wadu aslah al momin! ( Wadu is the weapon of a momin!) It is the duty of a momin to confront the satans that he is in mortal combat with them. Therefore he must always be clean and with valid wadu.

A person should always be with wadu, and if some time has passed after performing the ablution, he should renew it as a measure of carefulness that it might have gone void without the person noticing it. It is said, " Al wadu noor wal wadu alal wadu noor ala noor--- Wadu is a noor or light and performing a wadu over another is a bigger light. This is the light that dispels the darkness created by Satan in the hearts of the persons.