Changing one's intention during Salah

Q 2: What is the ruling on a man who, while offering a current obligatory Salah (Prayer), remembers that he has offered a previous one without being in a state of Wudu' (ablution)? Is it permissible for him to change his intention or what should he do?

A: If a person remembers, while they are performing a current obligatory Salah, that they offered a previous one while not being in a state of Taharah (ritual purification); they are to stop the current (Part No. 5; Page No. 101) Salah, pray the previous one, then pray the current Salah. This is because praying Salahs in order is Wajib (obligatory). Besides, it is impermissible for the man mentioned in the question to change his intention from one obligatory Salah to another while he is performing Salah. However, it is permissible for him to proceed with the current prayer intending that it is just a Nafilah (supererogatory) one. He is then to pray the two Salahs in their right order. If he fears the expiry of the time of the current Salah; he is to pray it first.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.