A Ma'mum following the Imam in Tashahhud

Q 3: I offered a four-Rak`ah Salah (Prayer consisting of four units) with the Imam (leader of congregational Prayer). In the first Tashahhud (testification recited in the sitting position in the second unit of Prayer), the Imam sat for a very long time, so I recited the complete formula of the last Tashahhud (testification recited in the sitting position in the last unit of Prayer). What is the ruling on my Salah? Should I repeat the Tashahhud, remain silent, or say a certain Du`a' (supplication)?

A: Your Salah is valid, and your first Tashahhud is also valid, as you followed your Imam. You should say the Tashahhud, invoke blessings upon the Prophet (peace be upon him) and remain silent until the Imam stands up.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.