Performing sajdah sahw after making a mistake in salaah

Q: I offered Isha prayer, but recited tashahhud between the two sujud in my second rakat. I decided to do sajdah sahw, but I forgot and completed my prayer. I was still facing the qiblah, but I removed my eye glasses, wiped my face and muttered to myself. Then I remembered to do sajdah sahw, and did it. Should I have done sajdah sahw? Will I have to repeat my prayer? 

A: It is valid.

And Allah Ta'ala (الله تعالى) knows best.

 

Answered by:

Mufti Ebrahim Salejee (Isipingo Beach)