One of the conditions of Wudu''

Q 3: What is the ruling when a person performs Wudu' (ablution) and when he finishes his Salah (Prayer), he discovers that he had forgotten to wash an organ whether obligatory or supererogatory?

A: Anyone who remembers that he has forgotten to wash any of the parts washed in Wudu' after having finished Salah must repeat Wudu' and Salah as well because Taharah (ritual purification) is a precondition for the validity of Salah. Taharah cannot be fulfilled except when all parts a person can wash are washed. The voluntary Salah is equally the same as the obligatory Salah except that it is not obligatory to make up for the voluntary Salah.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.